feat: batch queued planning edits (#375)

Merge pull request 'Keep Today plans convergent across tabs and devices' (#362) from timmy/361-convergent-today-sync into main

README.md

@@ -21,7 +21,11 @@ inspect/comment on assigned pull
 requests, merge assigned pull requests, and submit pull-request reviews.
 Pull-request replies and mobile My Work issue and PR comments use Gitea's
 issue-comment API; mobile issue capture requires issue
-creation and assignment permission. The New issue sheet can optionally select an open
+creation and assignment permission. Once a repository and meaningful title are selected,
+the New issue sheet checks for similar open issues in that repository. Candidate links keep
+the draft intact; the first create attempt pauses until the operator reviews them or explicitly
+chooses **Create anyway**. This check is advisory and never blocks offline capture or capture
+when search is unavailable. The sheet can also optionally select an open
 repository milestone and due date; the dashboard validates both and sends them with
 self-assignment in the single create request, so planned work appears in its release
 lane immediately. On a cold offline launch, **Save for filing** stores up to 20
@@ -32,7 +36,14 @@ and durable delivery flow. A different or unconfirmed account can only copy or d
 the private content. Issue capture and authored mobile actions (issue
 comments, pull-request comments, notification replies, and reviews) persist per-draft
 idempotency keys, so retrying after a timeout, reload, process restart, or handoff to
-another worker replays a confirmed result instead of posting duplicate content. When
+another worker replays a confirmed result instead of posting duplicate content. The ordered,
+five-item Today plan syncs across the operator's devices. Server revisions prevent delayed
+responses from replacing a newer plan; same-account browser tabs exchange fresh snapshots,
+and reconnecting or returning to the dashboard refreshes server truth after replaying queued
+offline operations. After a healthy, fully paginated
+My Work refresh proves that an item is complete or otherwise no longer eligible, Stackchain
+queues an idempotent retirement before removing it locally; partial and degraded refreshes
+leave the plan unchanged, and offline retirements replay after reconnect. When
 **Keep My Work available offline** is enabled, every issue or pull request in the bounded
 Today queue is warmed automatically after a healthy authenticated refresh and as soon as
 it is added. The readiness indicator reports saved, pending, and retryable items; unchanged
@@ -204,13 +215,17 @@ filter, preserves the selected release lane, shows the current draft count, resp
 the device safe area, and moves out of the way while a full-screen task is open.
 Desktop layout is unchanged.
 
-My Work also has a local **Later** queue. **Later today** defers an item for four
-hours, while **Tomorrow** returns it at 09:00 in the device's local timezone.
+My Work also has an account-synced **Later** queue. **Later today** defers an item for four
+hours, while **Tomorrow** returns it at 09:00 in the device's local timezone. **Choose date & time**
+accepts a valid future local date and time and returns the item at that exact instant; the picker
+shows the device timezone and rejects empty, normalized, invalid, or past values before saving.
 Deferred items leave normal and Attention queues without marking notifications read
 or changing any Gitea issue or pull request. They automatically return to their
 existing priority position at the wake time, and **Bring back now** restores them
-early. Later state is stored only in this browser, scoped to the confirmed Gitea
-login, and removed when fully loaded work confirms that an item no longer exists.
+early. Later wake times are scoped to the confirmed Gitea login and synchronize
+across signed-in tabs and devices. Offline changes apply immediately, survive reload,
+and replay after reconnect; `STACKCHAIN_LATER_DB` can override the default durable
+store at `.stackchain-state/later.sqlite3`.
 
 After one successful online load, the installed dashboard precaches a versioned,
 subpath-scoped application shell. During a network outage or a dashboard HTTP

frontend/create-issue-sheet.js

@@ -23,6 +23,9 @@ function createIssueCapture({ fetchJson, storage, createOperationId = newIssueOp
   const storageKey = 'stackchain.issue-capture.v1';
   const sharedStorageKey = 'stackchain.issue-share.v1';
   let pending = null;
+  let duplicateRequest = 0;
+  let duplicateState = {status: 'idle', key: '', candidates: []};
+  let acknowledgedDuplicateKey = '';
   const safeLabelIds = value => Array.from(new Set(
     (Array.isArray(value) ? value : []).filter(id => Number.isInteger(id) && id > 0)
   )).slice(0, 20);
@@ -140,6 +143,51 @@ function createIssueCapture({ fetchJson, storage, createOperationId = newIssueOp
     );
   }
 
+  function duplicateKey(draft) {
+    const repository = String(draft?.repository || '').trim();
+    const title = String(draft?.title || '').replace(/\s+/g, ' ').trim();
+    return { repository, title, key: repository + '\n' + title.toLowerCase() };
+  }
+
+  async function findDuplicates(draft) {
+    const input = duplicateKey(draft);
+    const request = ++duplicateRequest;
+    if (!input.repository || input.title.length < 4) {
+      duplicateState = {status: 'idle', key: input.key, candidates: []};
+      return duplicateState;
+    }
+    try {
+      const payload = await fetchJson('api/v1/search?q=' + encodeURIComponent(input.title) + '&limit=10');
+      if (request !== duplicateRequest) return {status: 'stale', key: input.key, candidates: []};
+      duplicateState = {
+        status: 'ready',
+        key: input.key,
+        partial: payload?.partial === true,
+        candidates: (Array.isArray(payload?.items) ? payload.items : []).filter(item =>
+          item?.kind === 'issue' && item?.state === 'open' && item?.repository === input.repository
+        ).slice(0, 3),
+      };
+      return duplicateState;
+    } catch (error) {
+      if (request !== duplicateRequest) return {status: 'stale', key: input.key, candidates: []};
+      duplicateState = {status: 'failed', key: input.key, candidates: [], error};
+      return duplicateState;
+    }
+  }
+
+  function needsDuplicateAcknowledgement(draft) {
+    const {key} = duplicateKey(draft);
+    return duplicateState.status === 'ready' && duplicateState.partial !== true && duplicateState.key === key &&
+      duplicateState.candidates.length > 0 && acknowledgedDuplicateKey !== key;
+  }
+
+  function acknowledgeDuplicates(draft) {
+    const {key} = duplicateKey(draft);
+    if (duplicateState.status === 'ready' && duplicateState.key === key && duplicateState.candidates.length) {
+      acknowledgedDuplicateKey = key;
+    }
+  }
+
   function submit(draft) {
     if (pending) return pending;
     const saved = saveDraft(draft);
@@ -166,7 +214,8 @@ function createIssueCapture({ fetchJson, storage, createOperationId = newIssueOp
   }
 
   return {
-    saveDraft, loadDraft, clearDraft, loadLabels, loadMilestones, submit,
+    saveDraft, loadDraft, clearDraft, loadLabels, loadMilestones, findDuplicates,
+    needsDuplicateAcknowledgement, acknowledgeDuplicates, submit,
     stageSharedContent, pendingSharedContent, acceptSharedContent, discardSharedContent,
   };
 }

frontend/dashboard.css

@@ -109,6 +109,14 @@ textarea { resize: vertical; min-height: 120px; }
 .detail-defer summary, .detail-defer button { min-height:44px; display:flex; align-items:center; justify-content:center; }
 .detail-defer summary { cursor:pointer; border:1px solid #60a5fa; border-radius:10px; font-weight:700; }
 .detail-defer-options { display:grid; grid-template-columns:repeat(auto-fit,minmax(120px,1fr)); gap:8px; margin-top:8px; }
+.later-picker { box-sizing:border-box; width:100%; height:100%; max-width:none; max-height:none; margin:0; padding:0; border:0; position:fixed; inset:0; z-index:90; display:flex; align-items:flex-end; justify-content:center; background:rgba(5,12,21,.78); backdrop-filter:blur(4px); }
+.later-picker[hidden] { display:none; }
+.later-picker-panel { box-sizing:border-box; width:min(560px,100%); max-height:100%; overflow:auto; display:grid; gap:12px; padding:18px; padding-bottom:calc(18px + env(safe-area-inset-bottom)); border:1px solid #2a496e; border-radius:18px 18px 0 0; background:#0b1526; }
+.later-picker-header { display:flex; align-items:center; justify-content:space-between; gap:12px; }
+.later-picker-header h2 { margin:0; }
+.later-picker input, .later-picker button { box-sizing:border-box; width:100%; min-height:44px; }
+.later-picker input { padding:10px; border:1px solid #2a496e; border-radius:10px; color:var(--text); background:#08111f; color-scheme:dark; font:inherit; }
+.later-picker-error { min-height:1.4em; color:#fca5a5; }
 .review-sheet-actions { position:sticky; bottom:0; z-index:3; padding:10px 4px; padding-bottom:calc(10px + env(safe-area-inset-bottom)); background:rgba(11,21,38,.98); border-top:1px solid #2a496e; }
 .mark-update-read { min-height:44px; width:100%; }
 .read-update { min-height:44px; width:100%; display:flex; align-items:center; justify-content:center; }
@@ -266,6 +274,12 @@ textarea { resize: vertical; min-height: 120px; }
 .create-issue-label-list { display:grid; grid-template-columns:repeat(auto-fit,minmax(140px,1fr)); gap:8px; }
 .create-issue-label-option { min-height:44px; display:flex !important; grid-template-columns:auto 1fr !important; align-items:center; gap:8px; padding:8px 10px; border:1px solid #2a496e; border-radius:10px; background:#10213a; }
 .create-issue-label-option input { width:20px; height:20px; margin:0; }
+.create-issue-duplicates { display:grid; gap:8px; min-width:0; padding:12px; border:1px solid #f59e0b; border-radius:10px; background:#2b210f; }
+.create-issue-duplicates[hidden] { display:none; }
+.create-issue-duplicate-list { display:grid; gap:8px; min-width:0; }
+.create-issue-duplicate-card { display:grid; gap:4px; min-width:0; padding:10px; border:1px solid #6b5220; border-radius:10px; background:#171d29; overflow-wrap:anywhere; }
+.create-issue-duplicate-card a, #create-issue-anyway { display:flex; align-items:center; min-height:44px; max-width:100%; }
+.create-issue-duplicate-card a { color:#93c5fd; }
 .create-issue-actions { position:sticky; bottom:0; display:grid; gap:8px; padding:10px 0; padding-bottom:calc(10px + env(safe-area-inset-bottom)); background:#0b1526; }
 .shared-content-conflict { display:grid; gap:8px; padding:12px; border:1px solid #8b5cf6; border-radius:10px; background:#16142b; }
 .shared-content-actions { display:grid; grid-template-columns:1fr 1fr; gap:8px; }

frontend/dashboard.js

@@ -135,6 +135,7 @@
   let activeMyWork = [];
   let laterMyWork = [];
   let todayMyWork = [];
+  const outboxCoordinator = createOutboxCoordinator({ storage: localStorage });
   const todayWork = createTodayWork({
     storage: localStorage,
     getLogin: () => planningOwnerLogin,
@@ -143,27 +144,54 @@
     storage: localStorage,
     getLogin: () => planningOwnerLogin,
     fetchJson: fetchReviewJson,
+    coordinator: outboxCoordinator,
     onRemoteIds: ids => {
       if (!planningOwnerLogin || !todayWork.replace(ids)) return;
       refreshMyWorkView();
       warmTodayOffline();
     },
-    onStatus: state => {
+    onStatus: (state, detail = {}) => {
       const status = qs('#today-sync-status');
       status.textContent = state === 'saved' ? 'Today saved to account.' :
-        (state === 'pending' ? 'Today saved on this device · sync pending.' :
+        (state === 'retrying' ? `Today saved on this device · retrying in ${Math.ceil(detail.delayMs / 1000)}s.` :
+          (state === 'pending' ? 'Today saved on this device · sync pending.' :
           (state === 'full' ? 'Another device filled Today · showing its saved plan.' :
-            'Today sync unavailable · changes stay on this device.'));
+            'Today sync unavailable · changes stay on this device.')));
     },
   });
+  todaySync.startLifecycle({ window, document });
   const laterWork = createLaterWork({
     storage: localStorage,
     getLogin: () => planningOwnerLogin,
+    onChange: (action, itemId, wakeAt) => {
+      if (laterSync.enqueue(action, itemId, wakeAt)) laterSync.flush();
+    },
+    onExpire: ids => {
+      const queued = ids.map(id => laterSync.enqueue('restore', id)).every(Boolean);
+      if (queued) laterSync.flush();
+    },
     onWake: () => {
       qs('#my-work-action-status').textContent = 'Deferred work is ready again.';
       refreshMyWorkView();
     },
   });
+  const laterSync = createLaterSync({
+    storage: localStorage,
+    getLogin: () => planningOwnerLogin,
+    fetchJson: fetchReviewJson,
+    coordinator: outboxCoordinator,
+    onRemoteRecords: records => {
+      if (!planningOwnerLogin || !laterWork.adopt(records)) return;
+      refreshMyWorkView();
+    },
+    onStatus: (state, detail = {}) => {
+      qs('#later-sync-status').textContent = state === 'saved' ? 'Later saved to account.' :
+        (state === 'retrying' ? `Later saved on this device · retrying in ${Math.ceil(detail.delayMs / 1000)}s.` :
+          (state === 'pending' ? 'Later saved on this device · sync pending.' :
+            'Later sync unavailable · changes stay on this device.'));
+    },
+  });
+  laterSync.startLifecycle({ window, document });
   document.addEventListener('visibilitychange', () => {
     if (!document.hidden) refreshMyWorkView();
   });
@@ -175,6 +203,8 @@
       const error = new Error(payload.error || payload.detail?.message || payload.detail || 'Review request failed.');
       error.status = response.status;
       error.code = payload.detail?.code;
+      const retryAfter = response.headers.get('Retry-After');
+      error.retryAfter = retryAfter === null ? undefined : Number(retryAfter);
       throw error;
     }
     return payload;
@@ -215,7 +245,6 @@
       await registration.sync.register('stackchain-issue-outbox-v1');
     };
   }
-  const outboxCoordinator = createOutboxCoordinator({ storage: localStorage });
   const issueOutbox = createIssueOutbox({
     storage: localStorage, fetchJson: fetchReviewJson, coordinator: outboxCoordinator,
     backgroundSync: backgroundIssueSync,
@@ -669,6 +698,54 @@
     announce: message => { qs('#my-work-action-status').textContent = message; },
     formatTime: fmt,
   });
+  const laterPickerElement = qs('#later-picker');
+  const laterPickerInput = qs('#later-picker-time');
+  const laterPicker = createLaterPicker({
+    history: window.history,
+    eventTarget: window,
+    onState: state => {
+      qs('#later-picker-error').textContent = state.message || '';
+      if (state.open) {
+        laterPickerInput.value = state.value || laterPickerInput.value;
+        qs('#later-picker-timezone').textContent = 'Times use ' +
+          (Intl.DateTimeFormat().resolvedOptions().timeZone || 'your device timezone') + '.';
+        laterPickerElement.hidden = false;
+        if (!laterPickerElement.open) laterPickerElement.showModal();
+        laterPickerInput.focus();
+      } else {
+        if (laterPickerElement.open) laterPickerElement.close();
+        laterPickerElement.hidden = true;
+      }
+    },
+    onConfirm: (item, until, context) => {
+      if (context === 'detail') {
+        const inSession = workSession.active();
+        const deferred = detailDefer.deferUntil(item, until, {
+          closeSheet:false,
+          restoreFocus:false,
+        });
+        if (!deferred) return false;
+        return inSession ? true : () => workRoute.close();
+      }
+      const result = laterWork.defer(item, until);
+      qs('#my-work-action-status').textContent = result === 'deferred' ?
+        'Deferred until ' + fmt(until) + '; work stays unread and unchanged in Gitea.' :
+        (result === 'invalid' ? 'Choose a valid future time.' : 'Could not save Later on this device.');
+      if (result !== 'deferred') return false;
+      refreshMyWorkView();
+      return true;
+    },
+  });
+  laterPicker.start();
+  qs('#later-picker-form').addEventListener('submit', event => {
+    event.preventDefault();
+    laterPicker.submit(laterPickerInput.value);
+  });
+  qs('#cancel-later-picker').addEventListener('click', () => laterPicker.close());
+  laterPickerElement.addEventListener('cancel', event => {
+    event.preventDefault();
+    laterPicker.close();
+  });
   document.querySelectorAll('[data-detail-defer-preset]').forEach(button => {
     button.addEventListener('click', () => {
       const item = selectedUpdate || selectedReview || selectedIssue || selectedPull;
@@ -676,6 +753,13 @@
       detailDefer.defer(item, button.dataset.detailDeferPreset);
     });
   });
+  document.querySelectorAll('[data-detail-defer-custom]').forEach(button => {
+    button.addEventListener('click', () => {
+      const item = selectedUpdate || selectedReview || selectedIssue || selectedPull;
+      button.closest('.detail-defer').open = false;
+      laterPicker.open(item, button, 'detail');
+    });
+  });
   document.querySelectorAll('[data-detail-defer-cancel]').forEach(button => {
     button.addEventListener('click', () => {
       const chooser = button.closest('.detail-defer');
@@ -685,7 +769,7 @@
   });
 
   function updatePlanningAvailability() {
-    document.querySelectorAll('[data-detail-defer-preset]').forEach(button => {
+    document.querySelectorAll('[data-detail-defer-preset], [data-detail-defer-custom]').forEach(button => {
       button.disabled = !planningOwnerLogin;
       button.toggleAttribute('data-planning-disabled', !planningOwnerLogin);
     });
@@ -811,8 +895,16 @@
     });
     activeMyWork = partitioned.active;
     laterMyWork = partitioned.later;
+    const authoritativeTodayReconciliation = liveMode && hasContextSnapshot &&
+      !lastContextSnapshot?.error &&
+      !Object.values(workPagination).some(page => page?.has_more);
     todayMyWork = todayWork.reconcile(lastMyWork, {
-      pruneMissing: !Object.values(workPagination).some(page => page?.has_more),
+      pruneMissing: authoritativeTodayReconciliation,
+      onPrune: retiredIds => {
+        const queued = retiredIds.map(id => todaySync.enqueue('remove', id)).every(Boolean);
+        if (queued) todaySync.flush();
+        return queued;
+      },
     });
     const counts = countMyWork(activeMyWork);
     counts.today = todayMyWork.length;
@@ -1010,7 +1102,7 @@
       const planningDisabled = planningOwnerLogin ? '' : ' disabled data-planning-disabled';
       const laterActions = selectedWorkFilter === 'later' ?
         '<div class="later-actions"><button type="button" data-later-restore data-work-index="' + index + '">Bring back now</button></div>' :
-        '<div class="later-actions" aria-label="Defer this work"><button type="button" data-later-preset="today" data-work-index="' + index + '"' + planningDisabled + '>Later today</button><button type="button" data-later-preset="tomorrow" data-work-index="' + index + '"' + planningDisabled + '>Tomorrow</button></div>';
+        '<div class="later-actions" aria-label="Defer this work"><button type="button" data-later-preset="today" data-work-index="' + index + '"' + planningDisabled + '>Later today</button><button type="button" data-later-preset="tomorrow" data-work-index="' + index + '"' + planningDisabled + '>Tomorrow</button><button type="button" data-later-custom data-work-index="' + index + '"' + planningDisabled + '>Choose date &amp; time</button></div>';
       const alreadyToday = todayWork.contains(item);
       const todayPosition = todayWork.position(item);
       const todayActions = selectedWorkFilter === 'today' ?
@@ -1078,6 +1170,17 @@
         refreshMyWorkView();
       });
     });
+    document.querySelectorAll('[data-later-custom]').forEach(button => {
+      button.addEventListener('click', () => {
+        const item = lastMyWork[Number(button.dataset.workIndex)];
+        if (!item) return;
+        if (!planningOwnerLogin) {
+          qs('#my-work-action-status').textContent = 'Planning is unavailable until your operator identity is restored.';
+          return;
+        }
+        laterPicker.open(item, button, 'card');
+      });
+    });
     document.querySelectorAll('[data-later-restore]').forEach(button => {
       button.addEventListener('click', () => {
         const item = lastMyWork[Number(button.dataset.workIndex)];
@@ -1616,6 +1719,67 @@
     });
   }
 
+  function currentIssueCaptureDraft() {
+    return {
+      repository: qs('#create-issue-repository').value,
+      title: qs('#create-issue-title').value.trim(),
+      body: qs('#create-issue-body').value.trim(),
+      labelIds: selectedIssueLabelIds(),
+      milestoneId: Number(qs('#create-issue-milestone').value) || null,
+      dueDate: qs('#create-issue-due-date').value,
+    };
+  }
+
+  let duplicateCheckTimer = null;
+  function renderIssueDuplicates(state) {
+    if (state.status === 'stale') return;
+    const panel = qs('#create-issue-duplicates');
+    const list = qs('#create-issue-duplicate-list');
+    const status = qs('#create-issue-duplicate-status');
+    const anyway = qs('#create-issue-anyway');
+    list.replaceChildren();
+    anyway.hidden = true;
+    if (state.status === 'idle') {
+      panel.hidden = true;
+      return;
+    }
+    panel.hidden = false;
+    if (state.status === 'failed') {
+      status.textContent = 'Could not check for existing issues. You can still create this issue.';
+      return;
+    }
+    if (!state.candidates.length) {
+      status.textContent = 'No similar open issues found in this repository.';
+      return;
+    }
+    status.textContent = (state.partial ? 'Search was incomplete. ' : '') + state.candidates.length +
+      ' similar open issue' + (state.candidates.length === 1 ? '' : 's') +
+      ' found. ' + (state.partial ? 'You can continue without waiting.' : 'Review before creating another.');
+    state.candidates.forEach(item => {
+      const card = document.createElement('article');
+      card.className = 'create-issue-duplicate-card';
+      const key = document.createElement('span');
+      key.className = 'small';
+      key.textContent = item.repository + ' #' + item.number;
+      const link = document.createElement('a');
+      link.textContent = item.title || 'Review existing issue';
+      link.href = safeSearchUrl(item.url) || '#';
+      link.target = '_blank';
+      link.rel = 'noopener noreferrer';
+      link.addEventListener('click', saveIssueCaptureDraft);
+      card.append(key, link);
+      list.appendChild(card);
+    });
+  }
+
+  function scheduleIssueDuplicateCheck() {
+    clearTimeout(duplicateCheckTimer);
+    const draft = currentIssueCaptureDraft();
+    duplicateCheckTimer = setTimeout(async () => {
+      renderIssueDuplicates(await issueCapture.findDuplicates(draft));
+    }, 350);
+  }
+
   async function loadIssueLabels(repository, selectedIds = []) {
     const list = qs('#create-issue-label-list');
     const status = qs('#create-issue-label-status');
@@ -1701,6 +1865,7 @@
     qs('#create-issue-due-date').value = captureDraft.dueDate || '';
     loadIssueLabels(qs('#create-issue-repository').value, captureDraft.labelIds);
     loadIssueMilestones(qs('#create-issue-repository').value, captureDraft.milestoneId);
+    scheduleIssueDuplicateCheck();
     qs('#create-issue-status').textContent = repositories.length ? '' : 'No accessible repositories are available.';
     qs('#submit-new-issue').disabled = !repositories.length;
     qs('#create-issue-sheet').classList.add('open');
@@ -1716,6 +1881,8 @@
       return;
     }
     qs('#create-issue-sheet').classList.remove('open');
+    clearTimeout(duplicateCheckTimer);
+    qs('#create-issue-duplicates').hidden = true;
     creatingIssue = false;
     qs('#new-issue').focus();
   }
@@ -2008,6 +2175,8 @@
       if (planningOwnerLogin) {
         todaySync.migrate(todayWork.read());
         todaySync.flush();
+        laterSync.migrate(laterWork.read());
+        laterSync.flush();
       }
       const contextIdentityFresh = !snapshot.context.error && !contextFreshness?.stale &&
         !contextFreshness?.degraded && !contextFreshness?.revalidating;
@@ -2462,30 +2631,39 @@
     closeCreateIssueSheet(true, !discardEditedDraft);
   });
   ['#create-issue-title', '#create-issue-body', '#create-issue-due-date'].forEach(selector =>
-    qs(selector).addEventListener('input', saveIssueCaptureDraft)
+    qs(selector).addEventListener('input', () => {
+      saveIssueCaptureDraft();
+      if (selector === '#create-issue-title') scheduleIssueDuplicateCheck();
+    })
   );
   qs('#create-issue-repository').addEventListener('change', event => {
     loadIssueLabels(event.target.value);
     loadIssueMilestones(event.target.value);
     saveIssueCaptureDraft();
+    scheduleIssueDuplicateCheck();
   });
   qs('#create-issue-label-list').addEventListener('change', saveIssueCaptureDraft);
   qs('#create-issue-milestone').addEventListener('change', saveIssueCaptureDraft);
+  qs('#create-issue-anyway').addEventListener('click', () => {
+    const captureDraft = currentIssueCaptureDraft();
+    issueCapture.acknowledgeDuplicates(captureDraft);
+    qs('#create-issue-anyway').hidden = true;
+    qs('#create-issue-form').requestSubmit();
+  });
   qs('#create-issue-form').addEventListener('submit', async event => {
     event.preventDefault();
-    const captureDraft = {
-      repository: qs('#create-issue-repository').value,
-      title: qs('#create-issue-title').value.trim(),
-      body: qs('#create-issue-body').value.trim(),
-      labelIds: selectedIssueLabelIds(),
-      milestoneId: Number(qs('#create-issue-milestone').value) || null,
-      dueDate: qs('#create-issue-due-date').value,
-    };
+    const captureDraft = currentIssueCaptureDraft();
     if (!captureDraft.repository || !captureDraft.title) {
       qs('#create-issue-status').textContent = 'Choose a repository and add a title.';
       qs('#create-issue-title').focus();
       return;
     }
+    if (issueCapture.needsDuplicateAcknowledgement(captureDraft)) {
+      qs('#create-issue-status').textContent = 'Review the possible existing issues, or choose Create anyway.';
+      qs('#create-issue-anyway').hidden = false;
+      qs('#create-issue-anyway').focus();
+      return;
+    }
     const button = qs('#submit-new-issue');
     button.disabled = true;
     qs('#create-issue-status').textContent = 'Saving for background delivery…';

frontend/detail-defer.js

@@ -8,21 +8,23 @@ function createDetailDefer({
   formatTime = value => new Date(value).toLocaleString(),
 }) {
   return {
-    defer(item, preset) {
+    deferUntil(item, until, { closeSheet = true, restoreFocus = true } = {}) {
       if (!item) return false;
-      const until = laterWork.presetUntil(preset);
       const result = laterWork.defer(item, until);
       if (result !== 'deferred') {
         announce(result === 'invalid' ? 'Choose a valid future time.' : 'Could not save Later on this device.');
         return false;
       }
       const inSession = session.active();
-      if (!inSession) close();
+      if (!inSession && closeSheet) close();
       refresh();
       announce('Deferred until ' + formatTime(until) + '. It stays unread and unchanged in Gitea.');
-      if (!inSession) focus();
+      if (!inSession && restoreFocus) focus();
       return true;
     },
+    defer(item, preset) {
+      return this.deferUntil(item, laterWork.presetUntil(preset));
+    },
   };
 }
 

frontend/index.html

@@ -100,6 +100,7 @@
     <button class="load-more-notifications" id="load-more-notifications" type="button" hidden>Load older updates</button>
     <div class="small" id="my-work-action-status" aria-live="assertive"></div>
     <div class="small" id="today-sync-status" aria-live="polite">Today is saved on this device.</div>
+    <div class="small" id="later-sync-status" aria-live="polite">Later is saved on this device.</div>
     <button class="retry-work-route" id="retry-work-route" type="button" hidden>Retry shared work item</button>
     <div class="small" id="work-route-share-status" aria-live="polite"></div>
     <div class="my-work-bulk" id="bulk-mark-read-bar" hidden>
@@ -293,7 +294,7 @@
       <button id="release-issue" type="button">Release assignment</button>
       <button id="close-issue" type="button">Close issue</button>
       <a id="open-issue-gitea" href="#" target="_blank" rel="noopener noreferrer">Open in Gitea</a>
-      <details class="detail-defer"><summary>Defer</summary><div class="detail-defer-options"><button type="button" data-detail-defer-preset="today" disabled data-planning-disabled>Later today</button><button type="button" data-detail-defer-preset="tomorrow" disabled data-planning-disabled>Tomorrow</button><button type="button" data-detail-defer-cancel>Cancel</button></div></details>
+      <details class="detail-defer"><summary>Defer</summary><div class="detail-defer-options"><button type="button" data-detail-defer-preset="today" disabled data-planning-disabled>Later today</button><button type="button" data-detail-defer-preset="tomorrow" disabled data-planning-disabled>Tomorrow</button><button type="button" data-detail-defer-custom disabled data-planning-disabled>Choose date &amp; time</button><button type="button" data-detail-defer-cancel>Cancel</button></div></details>
     </div>
     <nav class="work-session-nav" aria-label="Work session" hidden>
       <span class="small" aria-live="polite" data-work-session-progress></span>
@@ -354,6 +355,12 @@
         <div class="small" id="create-issue-label-status" aria-live="polite">Choose a repository to load labels.</div>
         <div class="create-issue-label-list" id="create-issue-label-list"></div>
       </fieldset>
+      <section class="create-issue-duplicates" id="create-issue-duplicates" aria-live="polite" hidden>
+        <strong>Possible existing issues</strong>
+        <div id="create-issue-duplicate-status" class="small"></div>
+        <div id="create-issue-duplicate-list" class="create-issue-duplicate-list"></div>
+        <button id="create-issue-anyway" type="button" hidden>Create anyway</button>
+      </section>
       <div class="small">The issue will be assigned to you.</div>
       <div class="create-issue-actions">
         <button id="save-unfiled-issue" type="button">Save for filing</button>
@@ -399,7 +406,7 @@
       <button class="share-work-route" type="button">Share</button>
       <button id="mark-update-read-next" type="button">Mark read &amp; next</button>
       <a id="open-update-gitea" href="#" target="_blank" rel="noopener noreferrer">Open in Gitea</a>
-      <details class="detail-defer"><summary>Defer</summary><div class="detail-defer-options"><button type="button" data-detail-defer-preset="today" disabled data-planning-disabled>Later today</button><button type="button" data-detail-defer-preset="tomorrow" disabled data-planning-disabled>Tomorrow</button><button type="button" data-detail-defer-cancel>Cancel</button></div></details>
+      <details class="detail-defer"><summary>Defer</summary><div class="detail-defer-options"><button type="button" data-detail-defer-preset="today" disabled data-planning-disabled>Later today</button><button type="button" data-detail-defer-preset="tomorrow" disabled data-planning-disabled>Tomorrow</button><button type="button" data-detail-defer-custom disabled data-planning-disabled>Choose date &amp; time</button><button type="button" data-detail-defer-cancel>Cancel</button></div></details>
     </div>
     <nav class="work-session-nav" aria-label="Work session" hidden>
       <span class="small" aria-live="polite" data-work-session-progress></span>
@@ -439,7 +446,7 @@
     <div class="pull-sheet-actions">
       <button class="share-work-route" type="button">Share</button>
       <a id="open-pull-gitea" href="#" target="_blank" rel="noopener noreferrer">Open in Gitea</a>
-      <details class="detail-defer"><summary>Defer</summary><div class="detail-defer-options"><button type="button" data-detail-defer-preset="today" disabled data-planning-disabled>Later today</button><button type="button" data-detail-defer-preset="tomorrow" disabled data-planning-disabled>Tomorrow</button><button type="button" data-detail-defer-cancel>Cancel</button></div></details>
+      <details class="detail-defer"><summary>Defer</summary><div class="detail-defer-options"><button type="button" data-detail-defer-preset="today" disabled data-planning-disabled>Later today</button><button type="button" data-detail-defer-preset="tomorrow" disabled data-planning-disabled>Tomorrow</button><button type="button" data-detail-defer-custom disabled data-planning-disabled>Choose date &amp; time</button><button type="button" data-detail-defer-cancel>Cancel</button></div></details>
     </div>
     <nav class="work-session-nav" aria-label="Work session" hidden>
       <span class="small" aria-live="polite" data-work-session-progress></span>
@@ -504,7 +511,7 @@
     </section>
     <h2>Review history</h2>
     <div id="review-history" class="muted"></div>
-    <div class="review-sheet-actions"><details class="detail-defer"><summary>Defer</summary><div class="detail-defer-options"><button type="button" data-detail-defer-preset="today" disabled data-planning-disabled>Later today</button><button type="button" data-detail-defer-preset="tomorrow" disabled data-planning-disabled>Tomorrow</button><button type="button" data-detail-defer-cancel>Cancel</button></div></details></div>
+    <div class="review-sheet-actions"><details class="detail-defer"><summary>Defer</summary><div class="detail-defer-options"><button type="button" data-detail-defer-preset="today" disabled data-planning-disabled>Later today</button><button type="button" data-detail-defer-preset="tomorrow" disabled data-planning-disabled>Tomorrow</button><button type="button" data-detail-defer-custom disabled data-planning-disabled>Choose date &amp; time</button><button type="button" data-detail-defer-cancel>Cancel</button></div></details></div>
     <nav class="work-session-nav" aria-label="Work session" hidden>
       <span class="small" aria-live="polite" data-work-session-progress></span>
       <button type="button" data-work-session-previous>Previous</button>
@@ -513,6 +520,18 @@
   </section>
 </div>
 
+<dialog class="later-picker" id="later-picker" role="dialog" aria-modal="true" aria-labelledby="later-picker-heading" hidden>
+  <form class="later-picker-panel" id="later-picker-form">
+    <div class="later-picker-header"><h2 id="later-picker-heading">Choose return time</h2><button id="cancel-later-picker" type="button">Cancel</button></div>
+    <p class="small">The item stays unread and unchanged in Gitea.</p>
+    <label for="later-picker-time">Return this work at</label>
+    <input id="later-picker-time" type="datetime-local" required />
+    <div class="small" id="later-picker-timezone"></div>
+    <div class="small later-picker-error" id="later-picker-error" aria-live="assertive"></div>
+    <button id="confirm-later-picker" type="submit">Defer until…</button>
+  </form>
+</dialog>
+
 <nav class="mobile-task-dock" id="mobile-task-dock" aria-label="Primary tasks">
   <button class="mobile-task-action" data-mobile-task="work" type="button" aria-current="page">Work <span class="mobile-task-count" id="mobile-attention-count" hidden>0</span></button>
   <button class="mobile-task-action" data-mobile-task="find" type="button">Find</button>
@@ -542,7 +561,9 @@
 <script src="static/today-sync.js"></script>
 <script src="static/update-ownership.js"></script>
 <script src="static/later-work.js"></script>
+<script src="static/later-sync.js"></script>
 <script src="static/detail-defer.js"></script>
+<script src="static/later-picker.js"></script>
 <script src="static/pick-work.js"></script>
 <script src="static/conversation.js"></script>
 <script src="static/issue-sheet.js"></script>

frontend/later-picker.js

@@ -0,0 +1,104 @@
+function createLaterPicker({
+  now = () => new Date(),
+  history = null,
+  eventTarget = null,
+  onState = () => {},
+  onConfirm = () => false,
+} = {}) {
+  let active = false;
+  let item = null;
+  let trigger = null;
+  let context = null;
+  let afterClose = null;
+  let committed = false;
+  let started = false;
+
+  function parse(input) {
+    const match = /^(\d{4})-(\d{2})-(\d{2})T(\d{2}):(\d{2})$/.exec(String(input || ''));
+    if (!match) return { ok:false, message:'Choose a valid local date and time.' };
+    const parts = match.slice(1).map(Number);
+    const value = new Date(parts[0], parts[1] - 1, parts[2], parts[3], parts[4], 0, 0);
+    const sameLocalTime = value.getFullYear() === parts[0] &&
+      value.getMonth() === parts[1] - 1 && value.getDate() === parts[2] &&
+      value.getHours() === parts[3] && value.getMinutes() === parts[4];
+    if (!sameLocalTime) return { ok:false, message:'Choose a valid local date and time.' };
+    if (value <= now()) return { ok:false, message:'Choose a future date and time.' };
+    return { ok:true, value };
+  }
+
+  function formatLocal(value) {
+    const pad = part => String(part).padStart(2, '0');
+    return value.getFullYear() + '-' + pad(value.getMonth() + 1) + '-' + pad(value.getDate()) +
+      'T' + pad(value.getHours()) + ':' + pad(value.getMinutes());
+  }
+
+  function deactivate() {
+    if (!active) return false;
+    const restore = trigger;
+    active = false;
+    item = null;
+    trigger = null;
+    context = null;
+    committed = false;
+    onState({ open:false, message:'' });
+    restore?.focus?.();
+    const cleanup = afterClose;
+    afterClose = null;
+    cleanup?.();
+    return true;
+  }
+
+  function start() {
+    if (started || !eventTarget) return;
+    started = true;
+    eventTarget.addEventListener('popstate', event => {
+      if (active && !event.state?.laterPicker) deactivate();
+    });
+    eventTarget.addEventListener('keydown', event => {
+      if (active && event.key === 'Escape') {
+        event.preventDefault?.();
+        close();
+      }
+    });
+  }
+
+  function open(nextItem, nextTrigger, nextContext = 'card') {
+    if (!nextItem || active) return false;
+    active = true;
+    item = nextItem;
+    trigger = nextTrigger || null;
+    context = nextContext;
+    committed = false;
+    const suggested = new Date(now().getTime() + 60 * 60 * 1000);
+    suggested.setMinutes(Math.ceil(suggested.getMinutes() / 15) * 15, 0, 0);
+    if (history) history.pushState({ ...(history.state || {}), laterPicker:true }, '');
+    onState({ open:true, message:'', value:formatLocal(suggested) });
+    return true;
+  }
+
+  function close() {
+    if (!active) return false;
+    if (history?.state?.laterPicker) history.back();
+    else deactivate();
+    return true;
+  }
+
+  function submit(input) {
+    if (!active || committed) return false;
+    const result = parse(input);
+    if (!result.ok) {
+      onState({ open:true, message:result.message, value:String(input || '') });
+      return false;
+    }
+    const confirmed = onConfirm(item, result.value, context);
+    if (confirmed !== true && typeof confirmed !== 'function') return false;
+    committed = true;
+    afterClose = typeof confirmed === 'function' ? confirmed : null;
+    close();
+    return true;
+  }
+
+  return { parse, start, open, close, submit, current:() => active };
+}
+
+if (typeof module !== 'undefined' && module.exports) module.exports = createLaterPicker;

frontend/later-sync.js

@@ -0,0 +1,247 @@
+function createLaterSync({ storage, getLogin, fetchJson, onRemoteRecords, onStatus, createOperationId, createChannel, coordinator,
+  setTimer = globalThis.setTimeout, clearTimer = globalThis.clearTimeout, retryBaseMs = 1000, retryMaxMs = 30000 }) {
+  const prefix = 'stackchain.later-sync.v1.';
+  const migrationPrefix = 'stackchain.later-sync-migrated.v1.';
+  const snapshotPrefix = 'stackchain.later-sync-snapshot.v1.';
+  let flushing = null;
+  let channel = null;
+  let channelKey = '';
+  let retryTimer = null;
+  let retryAttempt = 0;
+  const knownOperationKeys = new Set();
+
+  function cancelRetry() {
+    if (retryTimer !== null) clearTimer?.(retryTimer);
+    retryTimer = null;
+  }
+
+  function scheduleRetry(error, ownerKey) {
+    if (retryTimer !== null || !pending().length || !ownerKey) return;
+    const advised = Number(error?.retryAfter);
+    const delayMs = Number.isFinite(advised) && advised >= 0
+      ? advised * 1000
+      : Math.min(retryMaxMs, retryBaseMs * (2 ** retryAttempt));
+    retryAttempt += 1;
+    onStatus?.('retrying', { delayMs });
+    retryTimer = setTimer?.(async () => {
+      retryTimer = null;
+      if (key() !== ownerKey) return false;
+      return flush();
+    }, delayMs);
+    retryTimer?.unref?.();
+  }
+
+  function key() {
+    const login = String(getLogin?.() || '').trim().toLowerCase();
+    return login ? prefix + encodeURIComponent(login) : '';
+  }
+
+  function snapshotKey() {
+    const storageKey = key();
+    return storageKey ? snapshotPrefix + storageKey.slice(prefix.length) : '';
+  }
+
+  function savedRevision() {
+    try {
+      const snapshot = JSON.parse(storage?.getItem(snapshotKey()) || 'null');
+      return Number.isInteger(snapshot?.revision) ? snapshot.revision : -1;
+    } catch (_error) {
+      return -1;
+    }
+  }
+
+  function validRecords(records) {
+    return records && typeof records === 'object' && !Array.isArray(records);
+  }
+
+  function adopt(plan, broadcast = true) {
+    if (!Number.isInteger(plan?.revision) || !validRecords(plan?.records)) return false;
+    if (plan.revision < savedRevision()) return false;
+    const snapshot = { revision: plan.revision, records: plan.records };
+    try {
+      storage?.setItem(snapshotKey(), JSON.stringify(snapshot));
+    } catch (_error) {
+      // Server truth remains usable in this tab when storage is unavailable.
+    }
+    onRemoteRecords?.(plan.records);
+    if (broadcast) channel?.postMessage(snapshot);
+    return true;
+  }
+
+  function ensureChannel() {
+    const storageKey = key();
+    if (!storageKey || channelKey === storageKey) return;
+    channel?.close?.();
+    const factory = createChannel || (globalThis.window?.BroadcastChannel
+      ? name => new globalThis.window.BroadcastChannel(name)
+      : null);
+    channelKey = storageKey;
+    channel = factory?.('stackchain-later-' + storageKey.slice(prefix.length)) || null;
+    channel?.addEventListener?.('message', event => {
+      if (key() === storageKey) adopt(event.data, false);
+    });
+  }
+
+  function pending() {
+    const storageKey = key();
+    if (!storageKey || !storage) return [];
+    const recordPrefix = storageKey + '.operation.';
+    try {
+      const legacy = JSON.parse(storage.getItem(storageKey) || '[]');
+      if (Array.isArray(legacy)) {
+        legacy.forEach((operation, index) => {
+          if (!operation?.operation_id) return;
+          const recordKey = recordPrefix + encodeURIComponent(operation.operation_id);
+          storage.setItem(recordKey, JSON.stringify({ operation, queued_at: index }));
+          knownOperationKeys.add(recordKey);
+        });
+        if (legacy.length) storage.removeItem(storageKey);
+      }
+      const keys = new Set([...knownOperationKeys].filter(candidate => candidate.startsWith(recordPrefix)));
+      for (let index = 0; index < Number(storage.length || 0); index += 1) {
+        const candidate = storage.key?.(index);
+        if (candidate?.startsWith(recordPrefix)) keys.add(candidate);
+      }
+      const records = [...keys].map(recordKey => {
+        const record = JSON.parse(storage.getItem(recordKey) || 'null');
+        return record ? { ...record, recordKey } : null;
+      }).filter(record => record?.operation)
+        .sort((left, right) => Number(left.queued_at || 0) - Number(right.queued_at || 0) ||
+          left.operation.operation_id.localeCompare(right.operation.operation_id));
+      const latestByItem = new Map();
+      records.forEach(record => latestByItem.set(record.operation.item_id, record));
+      records.filter(record => latestByItem.get(record.operation.item_id) !== record).forEach(record => {
+        storage.removeItem(record.recordKey);
+        knownOperationKeys.delete(record.recordKey);
+      });
+      return records.filter(record => latestByItem.get(record.operation.item_id) === record)
+        .map(record => record.operation).filter(operation =>
+          operation && typeof operation.operation_id === 'string' &&
+          ['defer', 'restore'].includes(operation.action) && typeof operation.item_id === 'string' &&
+          (operation.action === 'restore' || typeof operation.wake_at === 'string'));
+    } catch (_error) {
+      return [];
+    }
+  }
+
+  function removeOperation(operationId) {
+    const storageKey = key();
+    if (!storageKey || !storage) return false;
+    const recordKey = storageKey + '.operation.' + encodeURIComponent(operationId);
+    try {
+      storage.removeItem(recordKey);
+      knownOperationKeys.delete(recordKey);
+      return true;
+    } catch (_error) {
+      return false;
+    }
+  }
+
+  function operationId() {
+    if (createOperationId) return createOperationId();
+    if (globalThis.crypto?.randomUUID) return globalThis.crypto.randomUUID();
+    return Date.now().toString(36) + '-' + Math.random().toString(36).slice(2);
+  }
+
+  function enqueue(action, itemId, wakeAt = null) {
+    if (!['defer', 'restore'].includes(action) || !itemId ||
+        (action === 'defer' && typeof wakeAt !== 'string')) return false;
+    pending().filter(operation => operation.item_id === itemId)
+      .forEach(operation => removeOperation(operation.operation_id));
+    const operation = { operation_id: operationId(), action, item_id: itemId, wake_at: wakeAt };
+    const storageKey = key();
+    if (!storageKey || !storage) return false;
+    const recordKey = storageKey + '.operation.' + encodeURIComponent(operation.operation_id);
+    let saved = false;
+    try {
+      storage.setItem(recordKey, JSON.stringify({ operation, queued_at: Date.now() }));
+      knownOperationKeys.add(recordKey);
+      saved = true;
+      coordinator?.notify('later');
+    } catch (_error) { /* Report the persistence failure below. */ }
+    onStatus?.(saved ? 'pending' : 'error');
+    return saved;
+  }
+
+  function migrate(records) {
+    const storageKey = key();
+    if (!storageKey || !storage) return false;
+    const marker = migrationPrefix + storageKey.slice(prefix.length);
+    try {
+      if (storage.getItem(marker)) return false;
+      Object.entries(records || {}).forEach(([itemId, wakeAt]) =>
+        enqueue('defer', itemId, wakeAt)
+      );
+      storage.setItem(marker, '1');
+      return true;
+    } catch (_error) {
+      return false;
+    }
+  }
+
+  async function run() {
+    const ownerKey = key();
+    if (!ownerKey) return false;
+    ensureChannel();
+    try {
+      let operations = pending();
+      let plan;
+      if (!operations.length) plan = await fetchJson('api/v1/later');
+      while (operations.length) {
+        if (key() !== ownerKey) return false;
+        const batch = operations.slice(0, 50);
+        plan = await fetchJson('api/v1/later', {
+          method: 'PATCH',
+          headers: { 'Content-Type': 'application/json' },
+          body: JSON.stringify({ operations: batch }),
+        });
+        const hasReceipts = Array.isArray(plan.accepted_operation_ids) ||
+          Array.isArray(plan.duplicate_operation_ids) || Array.isArray(plan.rejected_operations);
+        const received = hasReceipts ? [
+          ...(plan.accepted_operation_ids || []),
+          ...(plan.duplicate_operation_ids || []),
+          ...(plan.rejected_operations || []).map(item => item.operation_id),
+        ] : batch.map(item => item.operation_id);
+        for (const operationId of received) {
+          if (pending().some(candidate => candidate.operation_id === operationId) &&
+              !removeOperation(operationId)) {
+            throw new Error('Could not persist Later delivery receipt');
+          }
+        }
+        operations = pending();
+      }
+      adopt(plan);
+      onStatus?.(pending().length ? 'pending' : 'saved');
+      retryAttempt = 0;
+      cancelRetry();
+      return true;
+    } catch (error) {
+      if (pending().length) scheduleRetry(error, ownerKey);
+      else onStatus?.('error');
+      return false;
+    }
+  }
+
+  function flush() {
+    if (!flushing) {
+      const delivery = coordinator ? coordinator.runExclusive('later', run) : run();
+      flushing = Promise.resolve(delivery).finally(() => { flushing = null; });
+    }
+    return flushing;
+  }
+
+  function startLifecycle({ window: windowObject, document: documentObject }) {
+    windowObject?.addEventListener?.('online', flush);
+    documentObject?.addEventListener?.('visibilitychange', () =>
+      documentObject.hidden ? false : flush()
+    );
+  }
+
+  coordinator?.subscribe(change => {
+    if (change.queue === 'later' && pending().length) flush();
+  });
+
+  return { enqueue, migrate, flush, pending, startLifecycle };
+}
+
+if (typeof module !== 'undefined' && module.exports) module.exports = createLaterSync;

frontend/later-work.js

@@ -1,4 +1,4 @@
-function createLaterWork({ storage, getLogin, now = () => new Date(), setTimer = setTimeout, clearTimer = clearTimeout, onWake = () => {} }) {
+function createLaterWork({ storage, getLogin, now = () => new Date(), setTimer = setTimeout, clearTimer = clearTimeout, onWake = () => {}, onChange = () => {}, onExpire = () => {} }) {
   const prefix = 'stackchain.later-work.v1.';
   let timer = null;
 
@@ -45,8 +45,11 @@ function createLaterWork({ storage, getLogin, now = () => new Date(), setTimer =
     if (!key) return 'unavailable';
     if (!id || Number.isNaN(wake.getTime()) || wake <= now()) return 'invalid';
     const records = read();
-    records[id] = wake.toISOString();
-    return write(records) ? 'deferred' : 'unavailable';
+    const wakeAt = wake.toISOString();
+    records[id] = wakeAt;
+    if (!write(records)) return 'unavailable';
+    onChange('defer', id, wakeAt);
+    return 'deferred';
   }
 
   function presetUntil(preset) {
@@ -66,10 +69,21 @@ function createLaterWork({ storage, getLogin, now = () => new Date(), setTimer =
     const records = read();
     if (!id || !Object.prototype.hasOwnProperty.call(records, id)) return false;
     delete records[id];
-    write(records);
+    if (!write(records)) return false;
+    onChange('restore', id, null);
     return true;
   }
 
+  function adopt(records) {
+    if (!records || typeof records !== 'object' || Array.isArray(records)) return false;
+    const normalized = {};
+    Object.entries(records).forEach(([id, wake]) => {
+      const wakeTime = new Date(wake).getTime();
+      if (id && Number.isFinite(wakeTime)) normalized[id] = new Date(wakeTime).toISOString();
+    });
+    return write(normalized);
+  }
+
   function schedule(wakeTimes, current) {
     if (timer !== null) clearTimer(timer);
     timer = null;
@@ -87,16 +101,22 @@ function createLaterWork({ storage, getLogin, now = () => new Date(), setTimer =
     const available = new Map((items || []).map(item => [identity(item), item]));
     const retained = {};
     const wakeTimes = [];
+    const expired = [];
 
     Object.entries(records).forEach(([id, wake]) => {
       const wakeTime = new Date(wake).getTime();
-      if (!Number.isFinite(wakeTime) || wakeTime <= current) return;
+      if (!Number.isFinite(wakeTime) || wakeTime <= current) {
+        if (Number.isFinite(wakeTime)) expired.push(id);
+        return;
+      }
       if (pruneMissing && !available.has(id)) return;
       retained[id] = new Date(wakeTime).toISOString();
       wakeTimes.push(wakeTime);
     });
 
-    if (JSON.stringify(retained) !== JSON.stringify(records)) write(retained);
+    if (JSON.stringify(retained) !== JSON.stringify(records) && write(retained) && expired.length) {
+      onExpire(expired);
+    }
     schedule(wakeTimes, current);
     const deferredIds = new Set(Object.keys(retained));
     const active = (items || []).filter(item => !deferredIds.has(identity(item)));
@@ -107,7 +127,7 @@ function createLaterWork({ storage, getLogin, now = () => new Date(), setTimer =
     return { active, later };
   }
 
-  return { identity, defer, restore, presetUntil, partition };
+  return { identity, read, adopt, defer, restore, presetUntil, partition };
 }
 
 if (typeof module !== 'undefined' && module.exports) module.exports = createLaterWork;

frontend/outbox-coordinator.js

@@ -15,7 +15,7 @@ function createOutboxCoordinator({
   let sequence = 0;
 
   function validChange(value) {
-    return value && (value.queue === 'issue' || value.queue === 'authored') ? value : null;
+    return value && ['issue', 'authored', 'today', 'later'].includes(value.queue) ? value : null;
   }
 
   function publish(change) {

frontend/service-worker.js

@@ -1,6 +1,6 @@
 const BASE = new URL('./', self.location.href).pathname;
 importScripts(BASE + 'static/background-issue-sync.js');
-const CACHE = 'stackchain-dashboard-shell-v45';
+const CACHE = 'stackchain-dashboard-shell-v54';
 const OUTAGE_STATUSES = new Set([500, 502, 503, 504]);
 const NAVIGATION_TIMEOUT_MS = self.__STACKCHAIN_NAVIGATION_TIMEOUT_MS || 4000;
 const SHELL = [
@@ -28,7 +28,9 @@ const SHELL = [
   BASE + 'static/today-sync.js',
   BASE + 'static/update-ownership.js',
   BASE + 'static/later-work.js',
+  BASE + 'static/later-sync.js',
   BASE + 'static/detail-defer.js',
+  BASE + 'static/later-picker.js',
   BASE + 'static/pick-work.js',
   BASE + 'static/conversation.js',
   BASE + 'static/issue-sheet.js',

frontend/today-sync.js

@@ -1,34 +1,121 @@
-function createTodaySync({ storage, getLogin, fetchJson, onRemoteIds, onStatus, createOperationId }) {
+function createTodaySync({ storage, getLogin, fetchJson, onRemoteIds, onStatus, createOperationId, createChannel, coordinator,
+  setTimer = globalThis.setTimeout, clearTimer = globalThis.clearTimeout, retryBaseMs = 1000, retryMaxMs = 30000 }) {
   const prefix = 'stackchain.today-sync.v1.';
   const migrationPrefix = 'stackchain.today-sync-migrated.v1.';
+  const snapshotPrefix = 'stackchain.today-sync-snapshot.v1.';
   let flushing = null;
+  let channel = null;
+  let channelKey = '';
+  let retryTimer = null;
+  let retryAttempt = 0;
+  const knownOperationKeys = new Set();
+
+  function cancelRetry() {
+    if (retryTimer !== null) clearTimer?.(retryTimer);
+    retryTimer = null;
+  }
+
+  function scheduleRetry(error, ownerKey) {
+    if (retryTimer !== null || !pending().length || !ownerKey) return;
+    const advised = Number(error?.retryAfter);
+    const delayMs = Number.isFinite(advised) && advised >= 0
+      ? advised * 1000
+      : Math.min(retryMaxMs, retryBaseMs * (2 ** retryAttempt));
+    retryAttempt += 1;
+    onStatus?.('retrying', { delayMs });
+    retryTimer = setTimer?.(async () => {
+      retryTimer = null;
+      if (key() !== ownerKey) return false;
+      return flush();
+    }, delayMs);
+    retryTimer?.unref?.();
+  }
 
   function key() {
     const login = String(getLogin?.() || '').trim().toLowerCase();
     return login ? prefix + encodeURIComponent(login) : '';
   }
 
+  function snapshotKey() {
+    const storageKey = key();
+    return storageKey ? snapshotPrefix + storageKey.slice(prefix.length) : '';
+  }
+
+  function savedRevision() {
+    try {
+      const snapshot = JSON.parse(storage?.getItem(snapshotKey()) || 'null');
+      return Number.isInteger(snapshot?.revision) ? snapshot.revision : -1;
+    } catch (_error) {
+      return -1;
+    }
+  }
+
+  function adopt(plan, broadcast = true) {
+    if (!Number.isInteger(plan?.revision) || !Array.isArray(plan?.ids)) return false;
+    if (plan.revision < savedRevision()) return false;
+    try {
+      storage?.setItem(snapshotKey(), JSON.stringify({ revision: plan.revision, ids: plan.ids }));
+    } catch (_error) {
+      // A storage quota failure must not prevent the current tab from using server truth.
+    }
+    onRemoteIds?.(plan.ids);
+    if (broadcast) channel?.postMessage({ revision: plan.revision, ids: plan.ids });
+    return true;
+  }
+
+  function ensureChannel() {
+    const storageKey = key();
+    if (!storageKey || channelKey === storageKey) return;
+    channel?.close?.();
+    const factory = createChannel || (globalThis.window?.BroadcastChannel
+      ? name => new globalThis.window.BroadcastChannel(name)
+      : null);
+    channelKey = storageKey;
+    channel = factory?.('stackchain-today-' + storageKey.slice(prefix.length)) || null;
+    channel?.addEventListener?.('message', event => {
+      if (key() === storageKey) adopt(event.data, false);
+    });
+  }
+
   function pending() {
     const storageKey = key();
     if (!storageKey || !storage) return [];
+    const recordPrefix = storageKey + '.operation.';
     try {
-      const value = JSON.parse(storage.getItem(storageKey) || '[]');
-      return Array.isArray(value) ? value.filter(operation =>
-        operation && typeof operation.operation_id === 'string' &&
-        ['add', 'remove', 'move'].includes(operation.action) &&
-        typeof operation.item_id === 'string'
-      ) : [];
+      const legacy = JSON.parse(storage.getItem(storageKey) || '[]');
+      if (Array.isArray(legacy)) {
+        legacy.forEach((operation, index) => {
+          if (!operation?.operation_id) return;
+          const recordKey = recordPrefix + encodeURIComponent(operation.operation_id);
+          storage.setItem(recordKey, JSON.stringify({ operation, queued_at: index }));
+          knownOperationKeys.add(recordKey);
+        });
+        if (legacy.length) storage.removeItem(storageKey);
+      }
+      const keys = new Set([...knownOperationKeys].filter(candidate => candidate.startsWith(recordPrefix)));
+      for (let index = 0; index < Number(storage.length || 0); index += 1) {
+        const candidate = storage.key?.(index);
+        if (candidate?.startsWith(recordPrefix)) keys.add(candidate);
+      }
+      return [...keys].map(recordKey => JSON.parse(storage.getItem(recordKey) || 'null'))
+        .filter(record => record?.operation)
+        .sort((left, right) => Number(left.queued_at || 0) - Number(right.queued_at || 0) ||
+          left.operation.operation_id.localeCompare(right.operation.operation_id))
+        .map(record => record.operation)
+        .filter(operation => operation && typeof operation.operation_id === 'string' &&
+          ['add', 'remove', 'move'].includes(operation.action) && typeof operation.item_id === 'string');
     } catch (_error) {
       return [];
     }
   }
 
-  function save(operations) {
+  function removeOperation(operationId) {
     const storageKey = key();
     if (!storageKey || !storage) return false;
+    const recordKey = storageKey + '.operation.' + encodeURIComponent(operationId);
     try {
-      if (operations.length) storage.setItem(storageKey, JSON.stringify(operations));
-      else storage.removeItem(storageKey);
+      storage.removeItem(recordKey);
+      knownOperationKeys.delete(recordKey);
       return true;
     } catch (_error) {
       return false;
@@ -43,8 +130,23 @@ function createTodaySync({ storage, getLogin, fetchJson, onRemoteIds, onStatus,
 
   function enqueue(action, itemId, direction = null) {
     const operations = pending();
-    operations.push({ operation_id: operationId(), action, item_id: itemId, direction });
-    const saved = save(operations);
+    if (action === 'remove' && operations.some(operation =>
+      operation.action === 'remove' && operation.item_id === itemId
+    )) {
+      onStatus?.('pending');
+      return true;
+    }
+    const operation = { operation_id: operationId(), action, item_id: itemId, direction };
+    const storageKey = key();
+    if (!storageKey || !storage) return false;
+    const recordKey = storageKey + '.operation.' + encodeURIComponent(operation.operation_id);
+    let saved = false;
+    try {
+      storage.setItem(recordKey, JSON.stringify({ operation, queued_at: Date.now() }));
+      knownOperationKeys.add(recordKey);
+      saved = true;
+      coordinator?.notify('today');
+    } catch (_error) { /* Report the persistence failure below. */ }
     onStatus?.(saved ? 'pending' : 'error');
     return saved;
   }
@@ -64,43 +166,70 @@ function createTodaySync({ storage, getLogin, fetchJson, onRemoteIds, onStatus,
   }
 
   async function run() {
-    if (!key()) return false;
+    const ownerKey = key();
+    if (!ownerKey) return false;
+    ensureChannel();
     try {
-      let plan = await fetchJson('api/v1/today');
-      const operations = pending();
-      for (const operation of operations) {
-        try {
-          plan = await fetchJson('api/v1/today', {
-            method: 'PATCH',
-            headers: { 'Content-Type': 'application/json' },
-            body: JSON.stringify(operation),
-          });
-        } catch (error) {
-          if (error?.status !== 409) throw error;
-          const rejected = pending();
-          save(rejected.filter(candidate => candidate.operation_id !== operation.operation_id));
-          onRemoteIds?.(Array.isArray(plan.ids) ? plan.ids : []);
-          onStatus?.('full');
-          return false;
+      let operations = pending();
+      let plan;
+      let hadConflict = false;
+      if (!operations.length) plan = await fetchJson('api/v1/today');
+      while (operations.length) {
+        if (key() !== ownerKey) return false;
+        const batch = operations.slice(0, 50);
+        plan = await fetchJson('api/v1/today', {
+          method: 'PATCH',
+          headers: { 'Content-Type': 'application/json' },
+          body: JSON.stringify({ operations: batch }),
+        });
+        const hasReceipts = Array.isArray(plan.accepted_operation_ids) ||
+          Array.isArray(plan.duplicate_operation_ids) || Array.isArray(plan.rejected_operations);
+        const received = hasReceipts ? [
+          ...(plan.accepted_operation_ids || []),
+          ...(plan.duplicate_operation_ids || []),
+          ...(plan.rejected_operations || []).map(item => item.operation_id),
+        ] : batch.map(item => item.operation_id);
+        hadConflict = hadConflict || Boolean(plan.rejected_operations?.length);
+        for (const operationId of received) {
+          if (pending().some(candidate => candidate.operation_id === operationId) &&
+              !removeOperation(operationId)) {
+            throw new Error('Could not persist Today delivery receipt');
+          }
         }
-        const remaining = pending();
-        if (remaining[0]?.operation_id === operation.operation_id) save(remaining.slice(1));
+        operations = pending();
       }
-      onRemoteIds?.(Array.isArray(plan.ids) ? plan.ids : []);
-      onStatus?.(pending().length ? 'pending' : 'saved');
-      return true;
-    } catch (_error) {
-      onStatus?.(pending().length ? 'pending' : 'error');
+      adopt(plan);
+      onStatus?.(pending().length ? 'pending' : hadConflict ? 'full' : 'saved');
+      retryAttempt = 0;
+      cancelRetry();
+      return !hadConflict;
+    } catch (error) {
+      if (pending().length) scheduleRetry(error, ownerKey);
+      else onStatus?.('error');
       return false;
     }
   }
 
   function flush() {
-    if (!flushing) flushing = run().finally(() => { flushing = null; });
+    if (!flushing) {
+      const delivery = coordinator ? coordinator.runExclusive('today', run) : run();
+      flushing = Promise.resolve(delivery).finally(() => { flushing = null; });
+    }
     return flushing;
   }
 
-  return { enqueue, migrate, flush, pending };
+  function startLifecycle({ window: windowObject, document: documentObject }) {
+    windowObject?.addEventListener?.('online', flush);
+    documentObject?.addEventListener?.('visibilitychange', () =>
+      documentObject.hidden ? false : flush()
+    );
+  }
+
+  coordinator?.subscribe(change => {
+    if (change.queue === 'today' && pending().length) flush();
+  });
+
+  return { enqueue, migrate, flush, pending, startLifecycle };
 }
 
 if (typeof module !== 'undefined' && module.exports) module.exports = createTodaySync;

frontend/today-work.js

@@ -74,11 +74,15 @@ function createTodayWork({ storage, getLogin, limit = 5 }) {
     return write(ids);
   }
 
-  function reconcile(items, { pruneMissing = false } = {}) {
+  function reconcile(items, { pruneMissing = false, onPrune } = {}) {
     const available = new Map((items || []).map(item => [identity(item), item]));
     const ids = read();
     const retained = pruneMissing ? ids.filter(id => available.has(id)) : ids;
-    if (retained.length !== ids.length) write(retained);
+    const retired = ids.filter(id => !retained.includes(id));
+    if (retired.length) {
+      const reported = onPrune?.(retired);
+      if (reported !== false) write(retained);
+    }
     return retained.flatMap(id => available.has(id) ? [available.get(id)] : []);
   }
 

src/later_store.py

@@ -0,0 +1,190 @@
+"""Durable, account-scoped Later deferrals."""
+
+import json
+import sqlite3
+from datetime import datetime
+from pathlib import Path
+
+
+class LaterStore:
+    def __init__(self, path: str | Path, *, timeout: float = 1.0):
+        self.path = Path(path)
+        self.timeout = timeout
+
+    def _connect(self) -> sqlite3.Connection:
+        self.path.parent.mkdir(parents=True, exist_ok=True)
+        connection = sqlite3.connect(self.path, timeout=self.timeout)
+        connection.execute("PRAGMA journal_mode=WAL")
+        connection.execute(
+            """
+            CREATE TABLE IF NOT EXISTS later_plans (
+                login TEXT PRIMARY KEY,
+                revision INTEGER NOT NULL,
+                records TEXT NOT NULL
+            )
+            """
+        )
+        connection.execute(
+            """
+            CREATE TABLE IF NOT EXISTS later_operations (
+                login TEXT NOT NULL,
+                operation_id TEXT NOT NULL,
+                PRIMARY KEY (login, operation_id)
+            )
+            """
+        )
+        return connection
+
+    @staticmethod
+    def _normalize_login(login: str) -> str:
+        normalized = login.strip().lower()
+        if not normalized:
+            raise ValueError("login is required")
+        return normalized
+
+    @staticmethod
+    def _snapshot(row) -> dict:
+        if row is None:
+            return {"revision": 0, "records": {}}
+        return {"revision": int(row[0]), "records": json.loads(row[1])}
+
+    @staticmethod
+    def _validate_wake_at(wake_at: str | None) -> str:
+        if not wake_at:
+            raise ValueError("wake_at is required for defer")
+        try:
+            datetime.fromisoformat(wake_at.replace("Z", "+00:00"))
+        except ValueError as error:
+            raise ValueError("wake_at must be an ISO timestamp") from error
+        return wake_at
+
+    def get(self, login: str) -> dict:
+        with self._connect() as connection:
+            row = connection.execute(
+                "SELECT revision, records FROM later_plans WHERE login = ?",
+                (self._normalize_login(login),),
+            ).fetchone()
+        return self._snapshot(row)
+
+    def apply(
+        self,
+        login: str,
+        operation_id: str,
+        action: str,
+        item_id: str,
+        *,
+        wake_at: str | None = None,
+    ) -> dict:
+        login = self._normalize_login(login)
+        if not operation_id or not item_id:
+            raise ValueError("operation_id and item_id are required")
+        if action not in {"defer", "restore"}:
+            raise ValueError("unsupported Later action")
+        if action == "defer":
+            wake_at = self._validate_wake_at(wake_at)
+
+        with self._connect() as connection:
+            connection.execute("BEGIN IMMEDIATE")
+            row = connection.execute(
+                "SELECT revision, records FROM later_plans WHERE login = ?", (login,)
+            ).fetchone()
+            snapshot = self._snapshot(row)
+            duplicate = connection.execute(
+                "SELECT 1 FROM later_operations WHERE login = ? AND operation_id = ?",
+                (login, operation_id),
+            ).fetchone()
+            if duplicate:
+                return snapshot
+
+            records = dict(snapshot["records"])
+            before = records.get(item_id)
+            if action == "defer":
+                records[item_id] = wake_at
+                changed = before != wake_at
+            else:
+                changed = item_id in records
+                records.pop(item_id, None)
+
+            revision = snapshot["revision"] + (1 if changed else 0)
+            serialized = json.dumps(records, separators=(",", ":"), sort_keys=True)
+            if row is None:
+                connection.execute(
+                    "INSERT INTO later_plans(login, revision, records) VALUES (?, ?, ?)",
+                    (login, revision, serialized),
+                )
+            elif changed:
+                connection.execute(
+                    "UPDATE later_plans SET revision = ?, records = ? WHERE login = ?",
+                    (revision, serialized, login),
+                )
+            connection.execute(
+                "INSERT INTO later_operations(login, operation_id) VALUES (?, ?)",
+                (login, operation_id),
+            )
+            return {"revision": revision, "records": records}
+
+    def apply_batch(self, login: str, operations: list[dict]) -> dict:
+        """Apply ordered deferrals with one SQLite write transaction."""
+        login = self._normalize_login(login)
+        with self._connect() as connection:
+            connection.execute("BEGIN IMMEDIATE")
+            row = connection.execute(
+                "SELECT revision, records FROM later_plans WHERE login = ?", (login,)
+            ).fetchone()
+            snapshot = self._snapshot(row)
+            records = dict(snapshot["records"])
+            revision = snapshot["revision"]
+            accepted: list[str] = []
+            duplicates: list[str] = []
+
+            for operation in operations:
+                operation_id = operation.get("operation_id", "")
+                action = operation.get("action", "")
+                item_id = operation.get("item_id", "")
+                if not operation_id or not item_id:
+                    raise ValueError("operation_id and item_id are required")
+                if action not in {"defer", "restore"}:
+                    raise ValueError("unsupported Later action")
+                wake_at = operation.get("wake_at")
+                if action == "defer":
+                    wake_at = self._validate_wake_at(wake_at)
+                duplicate = connection.execute(
+                    "SELECT 1 FROM later_operations WHERE login = ? AND operation_id = ?",
+                    (login, operation_id),
+                ).fetchone()
+                if duplicate:
+                    duplicates.append(operation_id)
+                    continue
+
+                before = records.get(item_id)
+                if action == "defer":
+                    records[item_id] = wake_at
+                    changed = before != wake_at
+                else:
+                    changed = item_id in records
+                    records.pop(item_id, None)
+                revision += 1 if changed else 0
+                connection.execute(
+                    "INSERT INTO later_operations(login, operation_id) VALUES (?, ?)",
+                    (login, operation_id),
+                )
+                accepted.append(operation_id)
+
+            serialized = json.dumps(records, separators=(",", ":"), sort_keys=True)
+            if row is None:
+                connection.execute(
+                    "INSERT INTO later_plans(login, revision, records) VALUES (?, ?, ?)",
+                    (login, revision, serialized),
+                )
+            elif accepted:
+                connection.execute(
+                    "UPDATE later_plans SET revision = ?, records = ? WHERE login = ?",
+                    (revision, serialized, login),
+                )
+            return {
+                "revision": revision,
+                "records": records,
+                "accepted_operation_ids": accepted,
+                "duplicate_operation_ids": duplicates,
+                "rejected_operations": [],
+            }

src/main.py

@@ -35,6 +35,7 @@ from src.login_attempt_store import LoginAttemptStore, LoginAttemptStoreError, c
 from src.models import Issue, Milestone, PullRequest, Repo, User
 from src.request_boundary import RequestBodyLimitMiddleware, request_body_limit
 from src.suggestion_engine import compute
+from src.later_store import LaterStore
 from src.today_store import TodayPlanFull, TodayStore
 from src.views import router as frontend_router
 
@@ -216,6 +217,21 @@ class TodayOperation(BaseModel):
         return self
 
 
+class LaterOperation(BaseModel):
+    operation_id: str = Field(min_length=1, max_length=100)
+    action: Literal["defer", "restore"]
+    item_id: str = Field(min_length=1, max_length=500)
+    wake_at: str | None = Field(default=None, max_length=100)
+
+
+class TodayOperationBatch(BaseModel):
+    operations: list[TodayOperation] = Field(min_length=1, max_length=50)
+
+
+class LaterOperationBatch(BaseModel):
+    operations: list[LaterOperation] = Field(min_length=1, max_length=50)
+
+
 class NotificationReply(BaseModel):
     body: str = Field(min_length=1, max_length=10_000)
 
@@ -633,7 +649,7 @@ async def require_operator_session(request: Request, call_next):
 async def prevent_live_api_caching(request, call_next):
     response = await call_next(request)
     path = dashboard_auth.application_path(request)
-    if path in {"/api/v1/context", "/api/v1/background-identity", "/api/v1/events", "/api/v1/live", "/api/v1/available-issues", "/api/v1/search", "/api/v1/work-route", "/api/v1/today"} or path.startswith("/api/v1/work/") or (
+    if path in {"/api/v1/context", "/api/v1/background-identity", "/api/v1/events", "/api/v1/live", "/api/v1/available-issues", "/api/v1/search", "/api/v1/work-route", "/api/v1/today", "/api/v1/later"} or path.startswith("/api/v1/work/") or (
         path.startswith("/api/v1/repos/")
         and path.endswith("/review")
     ) or path.startswith("/api/v1/notifications") or (
@@ -861,6 +877,12 @@ def _today_store() -> TodayStore:
     )
 
 
+def _later_store() -> LaterStore:
+    return LaterStore(
+        os.getenv("STACKCHAIN_LATER_DB", str(_state_dir / "later.sqlite3"))
+    )
+
+
 async def _confirmed_login() -> str:
     try:
         user = await asyncio.wait_for(
@@ -883,14 +905,22 @@ async def get_today_plan():
         return await asyncio.to_thread(_today_store().get, login)
     except (OSError, sqlite3.Error):
         raise HTTPException(
-            status_code=503, detail="Today synchronization is unavailable"
+            status_code=503,
+            detail="Today synchronization is unavailable",
+            headers={"Retry-After": "1"},
         )
 
 
 @app.patch("/api/v1/today")
-async def update_today_plan(payload: TodayOperation):
+async def update_today_plan(payload: TodayOperation | TodayOperationBatch):
     login = await _confirmed_login()
     try:
+        if isinstance(payload, TodayOperationBatch):
+            return await asyncio.to_thread(
+                _today_store().apply_batch,
+                login,
+                [operation.model_dump() for operation in payload.operations],
+            )
         return await asyncio.to_thread(
             _today_store().apply,
             login,
@@ -903,7 +933,50 @@ async def update_today_plan(payload: TodayOperation):
         raise HTTPException(status_code=409, detail="Today is limited to 5 items")
     except (OSError, sqlite3.Error):
         raise HTTPException(
-            status_code=503, detail="Today synchronization is unavailable"
+            status_code=503,
+            detail="Today synchronization is unavailable",
+            headers={"Retry-After": "1"},
+        )
+
+
+@app.get("/api/v1/later")
+async def get_later_plan():
+    login = await _confirmed_login()
+    try:
+        return await asyncio.to_thread(_later_store().get, login)
+    except (OSError, sqlite3.Error):
+        raise HTTPException(
+            status_code=503,
+            detail="Later synchronization is unavailable",
+            headers={"Retry-After": "1"},
+        )
+
+
+@app.patch("/api/v1/later")
+async def update_later_plan(payload: LaterOperation | LaterOperationBatch):
+    login = await _confirmed_login()
+    try:
+        if isinstance(payload, LaterOperationBatch):
+            return await asyncio.to_thread(
+                _later_store().apply_batch,
+                login,
+                [operation.model_dump() for operation in payload.operations],
+            )
+        return await asyncio.to_thread(
+            _later_store().apply,
+            login,
+            payload.operation_id,
+            payload.action,
+            payload.item_id,
+            wake_at=payload.wake_at,
+        )
+    except ValueError as error:
+        raise HTTPException(status_code=422, detail=str(error))
+    except (OSError, sqlite3.Error):
+        raise HTTPException(
+            status_code=503,
+            detail="Later synchronization is unavailable",
+            headers={"Retry-After": "1"},
         )
 
 

src/today_store.py

@@ -128,3 +128,84 @@ class TodayStore:
                 (login, operation_id),
             )
             return {"revision": revision, "ids": ids}
+
+    def apply_batch(self, login: str, operations: list[dict]) -> dict:
+        """Apply an ordered batch with one lock and receipt per operation."""
+        login = self._normalize_login(login)
+        with self._connect() as connection:
+            connection.execute("BEGIN IMMEDIATE")
+            row = connection.execute(
+                "SELECT revision, ids FROM today_plans WHERE login = ?", (login,)
+            ).fetchone()
+            snapshot = self._snapshot(row)
+            ids = list(snapshot["ids"])
+            revision = snapshot["revision"]
+            accepted: list[str] = []
+            duplicates: list[str] = []
+            rejected: list[dict[str, str]] = []
+
+            for operation in operations:
+                operation_id = operation.get("operation_id", "")
+                action = operation.get("action", "")
+                item_id = operation.get("item_id", "")
+                direction = operation.get("direction")
+                if not operation_id or not item_id:
+                    raise ValueError("operation_id and item_id are required")
+                if action not in {"add", "remove", "move"}:
+                    raise ValueError("unsupported Today action")
+                if action == "move" and direction not in {"up", "down"}:
+                    raise ValueError("move direction must be up or down")
+                duplicate = connection.execute(
+                    "SELECT 1 FROM today_operations WHERE login = ? AND operation_id = ?",
+                    (login, operation_id),
+                ).fetchone()
+                if duplicate:
+                    duplicates.append(operation_id)
+                    continue
+
+                changed = False
+                if action == "add":
+                    if item_id not in ids:
+                        if len(ids) >= self.limit:
+                            rejected.append({"operation_id": operation_id, "reason": "today_full"})
+                            continue
+                        ids.append(item_id)
+                        changed = True
+                elif action == "remove":
+                    if item_id in ids:
+                        ids.remove(item_id)
+                        changed = True
+                else:
+                    try:
+                        index = ids.index(item_id)
+                    except ValueError:
+                        index = -1
+                    target = index - 1 if direction == "up" else index + 1
+                    if index >= 0 and 0 <= target < len(ids):
+                        ids[index], ids[target] = ids[target], ids[index]
+                        changed = True
+                revision += 1 if changed else 0
+                connection.execute(
+                    "INSERT INTO today_operations(login, operation_id) VALUES (?, ?)",
+                    (login, operation_id),
+                )
+                accepted.append(operation_id)
+
+            serialized = json.dumps(ids, separators=(",", ":"))
+            if row is None:
+                connection.execute(
+                    "INSERT INTO today_plans(login, revision, ids) VALUES (?, ?, ?)",
+                    (login, revision, serialized),
+                )
+            elif accepted:
+                connection.execute(
+                    "UPDATE today_plans SET revision = ?, ids = ? WHERE login = ?",
+                    (revision, serialized, login),
+                )
+            return {
+                "revision": revision,
+                "ids": ids,
+                "accepted_operation_ids": accepted,
+                "duplicate_operation_ids": duplicates,
+                "rejected_operations": rejected,
+            }

tests/test_later_picker.py

@@ -0,0 +1,134 @@
+import json
+import subprocess
+from pathlib import Path
+
+
+LATER_PICKER = Path(__file__).parents[1] / "frontend" / "later-picker.js"
+
+
+def run_node(script: str) -> dict:
+    result = subprocess.run(
+        ["node", "-e", script], check=True, capture_output=True, text=True
+    )
+    return json.loads(result.stdout)
+
+
+def test_exact_local_time_is_validated_and_converted_to_an_instant():
+    script = f"""
+const createLaterPicker = require({json.dumps(str(LATER_PICKER))});
+const picker = createLaterPicker({{
+  now: () => new Date(2026, 7, 9, 14, 0, 0),
+}});
+const valid = picker.parse('2026-08-09T16:30');
+const past = picker.parse('2026-08-09T13:59');
+const invalid = picker.parse('2026-02-30T12:00');
+process.stdout.write(JSON.stringify({{
+  valid: {{ok:valid.ok, local:[valid.value.getFullYear(), valid.value.getMonth() + 1, valid.value.getDate(), valid.value.getHours(), valid.value.getMinutes()]}},
+  past, invalid,
+}}));
+"""
+    output = run_node(script)
+
+    assert output["valid"] == {"ok": True, "local": [2026, 8, 9, 16, 30]}
+    assert output["past"] == {
+        "ok": False,
+        "message": "Choose a future date and time.",
+    }
+    assert output["invalid"] == {
+        "ok": False,
+        "message": "Choose a valid local date and time.",
+    }
+
+
+def test_picker_uses_history_for_cancel_and_confirms_only_valid_future_time():
+    script = f"""
+const createLaterPicker = require({json.dumps(str(LATER_PICKER))});
+const listeners = {{}};
+const states = [];
+const confirmed = [];
+let focused = 0;
+const history = {{
+  state: {{workRoute:'issue'}},
+  pushState(state) {{ this.state = state; states.push(['push', state.laterPicker]); }},
+  back() {{ states.push(['back']); const previous = {{workRoute:'issue'}}; this.state = previous; listeners.popstate({{state:previous}}); }},
+}};
+const picker = createLaterPicker({{
+  now: () => new Date(2026, 7, 9, 14, 0, 0), history,
+  eventTarget: {{addEventListener:(name, callback) => {{ listeners[name] = callback; }}}},
+  onState: state => states.push([state.open, state.message || '']),
+  onConfirm: (item, value, context) => {{ confirmed.push([item.number, value.toISOString(), context]); return true; }},
+}});
+picker.start();
+picker.open({{number:17}}, {{focus:() => {{ focused += 1; }}}}, 'detail');
+const invalid = picker.submit('2026-08-09T13:00');
+const valid = picker.submit('2026-08-09T16:30');
+picker.submit('2026-08-09T17:30');
+process.stdout.write(JSON.stringify({{invalid, valid, confirmed, focused, current:picker.current(), states}}));
+"""
+    output = run_node(script)
+
+    assert output["invalid"] is False
+    assert output["valid"] is True
+    assert output["confirmed"] == [[17, "2026-08-09T16:30:00.000Z", "detail"]]
+    assert output["focused"] == 1
+    assert output["current"] is False
+    assert [False, "Choose a future date and time."] not in output["states"]
+    assert [True, "Choose a future date and time."] in output["states"]
+    assert ["back"] in output["states"]
+
+
+def test_picker_runs_detail_cleanup_only_after_its_history_entry_closes():
+    script = f"""
+const createLaterPicker = require({json.dumps(str(LATER_PICKER))});
+const listeners = {{}};
+const order = [];
+const history = {{
+  state: {{workRoute:'issue'}},
+  pushState(state) {{ this.state = state; }},
+  back() {{
+    order.push('picker-back');
+    this.state = {{workRoute:'issue'}};
+    listeners.popstate({{state:this.state}});
+  }},
+}};
+const picker = createLaterPicker({{
+  now:() => new Date(2026, 7, 9, 14, 0), history,
+  eventTarget:{{addEventListener:(name, callback) => {{ listeners[name] = callback; }}}},
+  onConfirm:() => () => order.push('detail-close'),
+}});
+picker.start();
+picker.open({{number:17}}, null, 'detail');
+const saved = picker.submit('2026-08-09T16:30');
+process.stdout.write(JSON.stringify({{saved, order}}));
+"""
+    output = run_node(script)
+
+    assert output == {"saved": True, "order": ["picker-back", "detail-close"]}
+
+
+def test_picker_ignores_a_second_submit_while_browser_back_is_pending():
+    script = f"""
+const createLaterPicker = require({json.dumps(str(LATER_PICKER))});
+const listeners = {{}};
+let popstate;
+let confirmations = 0;
+const history = {{
+  state:null,
+  pushState(state) {{ this.state = state; }},
+  back() {{ popstate = () => {{ this.state = {{}}; listeners.popstate({{state:this.state}}); }}; }},
+}};
+const picker = createLaterPicker({{
+  now:() => new Date(2026, 7, 9, 14, 0), history,
+  eventTarget:{{addEventListener:(name, callback) => {{ listeners[name] = callback; }}}},
+  onConfirm:() => {{ confirmations += 1; return true; }},
+}});
+picker.start();
+picker.open({{number:17}});
+const first = picker.submit('2026-08-09T16:30');
+const second = picker.submit('2026-08-09T16:30');
+popstate();
+process.stdout.write(JSON.stringify({{first, second, confirmations}}));
+"""
+    output = run_node(script)
+
+    assert output == {"first": True, "second": False, "confirmations": 1}

tests/test_later_store.py

@@ -0,0 +1,150 @@
+import sqlite3
+
+import httpx
+import pytest
+
+from src import main
+from src.later_store import LaterStore
+
+
+@pytest.mark.anyio
+async def test_transient_later_store_failure_tells_clients_when_to_retry(monkeypatch):
+    async def user():
+        return {"login": "timmy"}
+
+    class BusyStore:
+        def apply(self, *_args, **_kwargs):
+            raise sqlite3.OperationalError("database is busy")
+
+    monkeypatch.setattr(main, "current_user", user)
+    monkeypatch.setattr(main, "_later_store", lambda: BusyStore())
+    payload = main.LaterOperation(
+        operation_id="retry-me",
+        action="defer",
+        item_id="issue:r:1:",
+        wake_at="2026-08-10T09:00:00.000Z",
+    )
+
+    with pytest.raises(main.HTTPException) as raised:
+        await main.update_later_plan(payload)
+
+    assert raised.value.status_code == 503
+    assert raised.value.headers == {"Retry-After": "1"}
+
+
+def test_deferrals_are_durable_revisioned_idempotent_and_account_scoped(tmp_path):
+    path = tmp_path / "later.sqlite3"
+    store = LaterStore(path)
+
+    deferred = store.apply(
+        "Timmy",
+        "op-1",
+        "defer",
+        "issue:stackchain/dashboard:363:",
+        wake_at="2026-08-10T09:00:00.000Z",
+    )
+    duplicate = store.apply(
+        "timmy",
+        "op-1",
+        "defer",
+        "issue:stackchain/dashboard:363:",
+        wake_at="2026-08-11T09:00:00.000Z",
+    )
+
+    assert duplicate == deferred == {
+        "revision": 1,
+        "records": {
+            "issue:stackchain/dashboard:363:": "2026-08-10T09:00:00.000Z"
+        },
+    }
+    assert LaterStore(path).get("timmy") == deferred
+    assert store.get("alexander") == {"revision": 0, "records": {}}
+
+    assert store.apply(
+        "timmy", "op-2", "restore", "issue:stackchain/dashboard:363:"
+    ) == {"revision": 2, "records": {}}
+
+
+def test_batch_applies_in_one_ordered_idempotent_unit(tmp_path):
+    store = LaterStore(tmp_path / "later.sqlite3")
+    operations = [
+        {"operation_id": "first", "action": "defer", "item_id": "issue:r:1:", "wake_at": "2026-08-10T09:00:00.000Z"},
+        {"operation_id": "second", "action": "restore", "item_id": "issue:r:1:"},
+    ]
+
+    result = store.apply_batch("timmy", operations)
+    assert result == {
+        "revision": 2,
+        "records": {},
+        "accepted_operation_ids": ["first", "second"],
+        "duplicate_operation_ids": [],
+        "rejected_operations": [],
+    }
+    replay = store.apply_batch("timmy", operations)
+    assert replay["revision"] == 2
+    assert replay["accepted_operation_ids"] == []
+    assert replay["duplicate_operation_ids"] == ["first", "second"]
+
+
+@pytest.mark.anyio
+async def test_authenticated_later_api_uses_confirmed_account_and_csrf(monkeypatch, tmp_path):
+    monkeypatch.setenv("STACKCHAIN_DASHBOARD_AUTH_MODE", "operator")
+    monkeypatch.setenv("STACKCHAIN_DASHBOARD_ACCESS_TOKEN", "correct horse battery staple")
+    monkeypatch.setenv(
+        "STACKCHAIN_DASHBOARD_SESSION_SECRET",
+        "a-separate-session-signing-secret-with-enough-entropy",
+    )
+    monkeypatch.setenv("STACKCHAIN_SESSION_DB", str(tmp_path / "sessions.sqlite3"))
+    monkeypatch.setenv("STACKCHAIN_LOGIN_ATTEMPT_DB", str(tmp_path / "login.sqlite3"))
+    monkeypatch.setenv("STACKCHAIN_LATER_DB", str(tmp_path / "later.sqlite3"))
+
+    async def user():
+        return {"id": 1, "login": "Timmy"}
+
+    monkeypatch.setattr(main, "current_user", user)
+    transport = httpx.ASGITransport(app=main.app)
+    async with httpx.AsyncClient(transport=transport, base_url="https://test") as client:
+        await client.post(
+            "/api/v1/session", json={"access_token": "correct horse battery staple"}
+        )
+        forbidden = await client.patch(
+            "/api/v1/later",
+            json={
+                "operation_id": "mobile-1",
+                "action": "defer",
+                "item_id": "issue:stackchain/dashboard:363:",
+                "wake_at": "2026-08-10T09:00:00.000Z",
+            },
+        )
+        changed = await client.patch(
+            "/api/v1/later",
+            json={
+                "operations": [
+                    {"operation_id": "mobile-1", "action": "defer", "item_id": "issue:stackchain/dashboard:363:", "wake_at": "2026-08-10T09:00:00.000Z"},
+                    {"operation_id": "mobile-2", "action": "defer", "item_id": "issue:stackchain/dashboard:365:", "wake_at": "2026-08-11T09:00:00.000Z"},
+                ],
+            },
+            headers={
+                "Origin": "https://test",
+                "X-CSRF-Token": client.cookies["stackchain_csrf"],
+            },
+        )
+        fetched = await client.get("/api/v1/later")
+
+    assert forbidden.status_code == 403
+    assert changed.status_code == 200
+    assert changed.json() == {
+        "revision": 2,
+        "records": {
+            "issue:stackchain/dashboard:363:": "2026-08-10T09:00:00.000Z",
+            "issue:stackchain/dashboard:365:": "2026-08-11T09:00:00.000Z",
+        },
+        "accepted_operation_ids": ["mobile-1", "mobile-2"],
+        "duplicate_operation_ids": [],
+        "rejected_operations": [],
+    }
+    assert fetched.json() == {"revision": 2, "records": {
+        "issue:stackchain/dashboard:363:": "2026-08-10T09:00:00.000Z",
+        "issue:stackchain/dashboard:365:": "2026-08-11T09:00:00.000Z",
+    }}
+    assert fetched.headers["cache-control"] == "no-store"

tests/test_later_sync.py

@@ -0,0 +1,292 @@
+import json
+import subprocess
+from pathlib import Path
+
+import pytest
+
+from tests.dashboard_bundle import dashboard
+
+
+LATER_SYNC = Path(__file__).parents[1] / "frontend" / "later-sync.js"
+LATER_WORK = Path(__file__).parents[1] / "frontend" / "later-work.js"
+COORDINATOR = Path(__file__).parents[1] / "frontend" / "outbox-coordinator.js"
+
+
+def run_node(script):
+    return json.loads(
+        subprocess.run(
+            ["node", "-e", script], check=True, capture_output=True, text=True
+        ).stdout
+    )
+
+
+def test_two_tabs_cannot_erase_each_others_later_edits_or_double_drain():
+    script = f"""
+const createLaterSync=require({json.dumps(str(LATER_SYNC))});
+const createCoordinator=require({json.dumps(str(COORDINATOR))});
+const values=new Map();const storage={{get length(){{return values.size}},key:i=>[...values.keys()][i]||null,getItem:k=>values.get(k)||null,setItem:(k,v)=>values.set(k,v),removeItem:k=>values.delete(k)}};
+const channels=[];const channelFactory=()=>{{const channel={{onmessage:null,postMessage:data=>channels.filter(x=>x!==channel).forEach(x=>x.onmessage?.({{data}})),close(){{}}}};channels.push(channel);return channel}};
+const held=new Set();const locks={{request:async(name,_options,work)=>{{if(held.has(name))return work(null);held.add(name);try{{return await work({{name}})}}finally{{held.delete(name)}}}}}};
+let sequence=0,releaseFirst;const delivered=[];
+const make=tab=>createLaterSync({{storage,getLogin:()=> 'timmy',createOperationId:()=>tab+'-'+(++sequence),coordinator:createCoordinator({{storage,locks,channelFactory,tabId:tab}}),fetchJson:async(_url,options={{}})=>{{if(!options.method)return {{revision:0,records:{{}}}};const operation=JSON.parse(options.body).operations[0];delivered.push(operation);if(delivered.length===1)await new Promise(resolve=>releaseFirst=resolve);return {{revision:delivered.length,records:{{[operation.item_id]:operation.wake_at}}}}}},onRemoteRecords:()=>{{}},onStatus:()=>{{}}}});
+const first=make('first'),second=make('second');first.enqueue('defer','issue:r:1:','2026-08-10T09:00:00.000Z');
+(async()=>{{const draining=first.flush();while(!releaseFirst)await Promise.resolve();second.enqueue('defer','issue:r:2:','2026-08-11T09:00:00.000Z');const competing=second.flush();releaseFirst();await Promise.all([draining,competing]);await first.flush();process.stdout.write(JSON.stringify({{delivered,pending:first.pending(),keys:[...values.keys()]}}));}})();
+"""
+    result = run_node(script)
+    assert sorted(operation["operation_id"] for operation in result["delivered"]) == ["first-1", "second-2"]
+    assert len(result["delivered"]) == 2
+    assert result["pending"] == []
+    assert not any(".operation." in key for key in result["keys"])
+
+
+def test_concurrent_later_records_for_one_item_deliver_only_the_newest_intent():
+    script = f"""
+const createLaterSync=require({json.dumps(str(LATER_SYNC))});
+const values=new Map();const storage={{get length(){{return values.size}},key:i=>[...values.keys()][i]||null,getItem:k=>values.get(k)||null,setItem:(k,v)=>values.set(k,v),removeItem:k=>values.delete(k)}};
+const prefix='stackchain.later-sync.v1.timmy.operation.';
+values.set(prefix+'old',JSON.stringify({{queued_at:100,operation:{{operation_id:'old',action:'defer',item_id:'issue:r:2:',wake_at:'2026-08-10T09:00:00.000Z'}}}}));
+values.set(prefix+'new',JSON.stringify({{queued_at:101,operation:{{operation_id:'new',action:'restore',item_id:'issue:r:2:',wake_at:null}}}}));
+const delivered=[];const sync=createLaterSync({{storage,getLogin:()=> 'timmy',fetchJson:async(_url,options={{}})=>{{if(!options.method)return {{revision:0,records:{{}}}};delivered.push(...JSON.parse(options.body).operations);return {{revision:1,records:{{}}}}}},onRemoteRecords:()=>{{}},onStatus:()=>{{}}}});
+(async()=>{{await sync.flush();process.stdout.write(JSON.stringify({{delivered,pending:sync.pending(),keys:[...values.keys()]}}));}})();
+"""
+    result = run_node(script)
+    assert [operation["operation_id"] for operation in result["delivered"]] == ["new"]
+    assert result["pending"] == []
+    assert not any(".operation." in key for key in result["keys"])
+
+
+def test_offline_deferral_replays_once_and_adopts_server_records():
+    script = f"""
+const createLaterSync = require({json.dumps(str(LATER_SYNC))});
+const values = new Map();
+const requests = [];
+let remote = {{revision:1,records:{{'issue:r:9:':'2026-08-11T09:00:00.000Z'}}}};
+const sync = createLaterSync({{
+  storage:{{getItem:k=>values.get(k)||null,setItem:(k,v)=>values.set(k,v),removeItem:k=>values.delete(k)}},
+  getLogin:()=> 'timmy', createOperationId:()=> 'offline-op',
+  fetchJson:async (url,options={{}})=>{{
+    requests.push({{url,body:options.body&&JSON.parse(options.body)}});
+    if (!options.method) return remote;
+    const operation=JSON.parse(options.body).operations[0];
+    remote={{revision:2,records:{{...remote.records,[operation.item_id]:operation.wake_at}}}};
+    return remote;
+  }},
+  onRemoteRecords:records=>{{globalThis.records=records}},
+  onStatus:status=>{{globalThis.status=status}},
+}});
+sync.enqueue('defer','issue:r:2:','2026-08-10T09:00:00.000Z');
+(async()=>{{await sync.flush();await sync.flush();process.stdout.write(JSON.stringify({{
+  requests,records:globalThis.records,status:globalThis.status,pending:sync.pending()
+}}));}})();
+"""
+    result = run_node(script)
+
+    assert [request["url"] for request in result["requests"]] == [
+        "api/v1/later",
+        "api/v1/later",
+    ]
+    assert result["requests"][0]["body"] == {"operations": [{
+        "operation_id": "offline-op",
+        "action": "defer",
+        "item_id": "issue:r:2:",
+        "wake_at": "2026-08-10T09:00:00.000Z",
+    }]}
+    assert result["records"]["issue:r:2:"] == "2026-08-10T09:00:00.000Z"
+    assert result["status"] == "saved"
+    assert result["pending"] == []
+
+
+def test_pending_later_edits_are_sent_as_one_batch_without_a_preflight_get():
+    script = f"""
+const createLaterSync=require({json.dumps(str(LATER_SYNC))});
+const values=new Map();const requests=[];let sequence=0;
+const sync=createLaterSync({{
+ storage:{{getItem:k=>values.get(k)||null,setItem:(k,v)=>values.set(k,v),removeItem:k=>values.delete(k)}},
+ getLogin:()=> 'timmy',createOperationId:()=> 'op-'+(++sequence),
+ fetchJson:async(_url,options={{}})=>{{const body=JSON.parse(options.body);requests.push(body);return {{revision:2,records:{{}},accepted_operation_ids:body.operations.map(x=>x.operation_id),duplicate_operation_ids:[],rejected_operations:[]}}}},
+ onRemoteRecords:()=>{{}},onStatus:()=>{{}},
+}});
+sync.enqueue('defer','issue:r:1:','2026-08-10T09:00:00.000Z');
+sync.enqueue('restore','issue:r:2:');
+(async()=>{{await sync.flush();process.stdout.write(JSON.stringify({{requests,pending:sync.pending()}}));}})();
+"""
+    result=run_node(script)
+    assert len(result["requests"]) == 1
+    assert [item["operation_id"] for item in result["requests"][0]["operations"]] == ["op-1", "op-2"]
+    assert result["pending"] == []
+
+
+def test_latest_offline_intent_wins_and_failed_delivery_stays_pending():
+    script = f"""
+const createLaterSync = require({json.dumps(str(LATER_SYNC))});
+const values=new Map(); let sequence=0;
+const sync=createLaterSync({{
+ storage:{{getItem:k=>values.get(k)||null,setItem:(k,v)=>values.set(k,v),removeItem:k=>values.delete(k)}},
+ getLogin:()=> 'timmy',createOperationId:()=> 'op-'+(++sequence),
+ fetchJson:async()=>{{throw new Error('offline')}},onRemoteRecords:()=>{{}},onStatus:s=>{{globalThis.status=s}},
+}});
+sync.enqueue('defer','issue:r:2:','2026-08-10T09:00:00.000Z');
+sync.enqueue('restore','issue:r:2:');
+(async()=>{{await sync.flush();process.stdout.write(JSON.stringify({{pending:sync.pending(),status:globalThis.status}}));}})();
+"""
+    assert run_node(script) == {
+        "pending": [
+            {
+                "operation_id": "op-2",
+                "action": "restore",
+                "item_id": "issue:r:2:",
+                "wake_at": None,
+            }
+        ],
+        "status": "retrying",
+    }
+
+
+def test_retry_is_single_flight_and_does_not_cross_account_boundary():
+    script = f"""
+const createLaterSync = require({json.dumps(str(LATER_SYNC))});
+const values=new Map(); const timers=[]; const requests=[]; let login='timmy';
+const sync=createLaterSync({{
+ storage:{{getItem:k=>values.get(k)||null,setItem:(k,v)=>values.set(k,v),removeItem:k=>values.delete(k)}},
+ getLogin:()=>login,createOperationId:()=> 'stable-later-op',
+ setTimer:(callback,delay)=>{{timers.push({{callback,delay}});return timers.length}},clearTimer:()=>{{}},
+ fetchJson:async (_url,options={{}})=>{{requests.push(options.method||'GET');throw new Error('offline')}},
+ onRemoteRecords:()=>{{}},onStatus:()=>{{}},
+}});
+sync.enqueue('defer','issue:r:2:','2026-08-10T09:00:00.000Z');
+(async()=>{{
+ const first=sync.flush(); const same=sync.flush(); await Promise.all([first,same]);
+ const scheduledBeforeSwitch=timers.length;
+ login='alexander'; await timers[0].callback();
+ process.stdout.write(JSON.stringify({{scheduledBeforeSwitch,timers:timers.length,requests,pendingForAlexander:sync.pending()}}));
+}})();
+"""
+    assert run_node(script) == {
+        "scheduledBeforeSwitch": 1,
+        "timers": 1,
+        "requests": ["PATCH"],
+        "pendingForAlexander": [],
+    }
+
+
+def test_change_queued_during_delivery_is_drained_before_flush_settles():
+    script = f"""
+const createLaterSync=require({json.dumps(str(LATER_SYNC))});
+const values=new Map(); const actions=[]; let sequence=0; let releaseFirst;
+const sync=createLaterSync({{
+ storage:{{getItem:k=>values.get(k)||null,setItem:(k,v)=>values.set(k,v),removeItem:k=>values.delete(k)}},
+ getLogin:()=> 'timmy',createOperationId:()=> 'op-'+(++sequence),
+ fetchJson:async (_url,options={{}})=>{{
+   if (!options.method) return {{revision:0,records:{{}}}};
+   const operation=JSON.parse(options.body).operations[0]; actions.push(operation.action);
+   if (operation.action==='defer') await new Promise(resolve=>releaseFirst=resolve);
+   return {{revision:actions.length,records:operation.action==='defer'?{{[operation.item_id]:operation.wake_at}}:{{}}}};
+ }},onRemoteRecords:r=>{{globalThis.records=r}},onStatus:()=>{{}},
+}});
+sync.enqueue('defer','issue:r:2:','2026-08-10T09:00:00.000Z');
+(async()=>{{const flushing=sync.flush();while(!releaseFirst) await Promise.resolve();
+sync.enqueue('restore','issue:r:2:');releaseFirst();await flushing;
+process.stdout.write(JSON.stringify({{actions,pending:sync.pending(),records:globalThis.records}}));}})();
+"""
+    assert run_node(script) == {
+        "actions": ["defer", "restore"],
+        "pending": [],
+        "records": {},
+    }
+
+
+def test_tabs_reject_an_older_snapshot_after_a_newer_revision():
+    script = f"""
+const createLaterSync=require({json.dumps(str(LATER_SYNC))});
+const values=new Map();
+const storage={{getItem:k=>values.get(k)||null,setItem:(k,v)=>values.set(k,v),removeItem:k=>values.delete(k)}};
+const listeners=[];
+const createChannel=()=>({{addEventListener:(_n,h)=>listeners.push(h),postMessage:data=>listeners.forEach(h=>h({{data}}))}});
+let resolveOld,resolveNew; const oldHistory=[],newHistory=[];
+const oldTab=createLaterSync({{storage,getLogin:()=> 'timmy',createChannel,fetchJson:()=>new Promise(r=>resolveOld=r),onRemoteRecords:r=>oldHistory.push(r),onStatus:()=>{{}}}});
+const newTab=createLaterSync({{storage,getLogin:()=> 'timmy',createChannel,fetchJson:()=>new Promise(r=>resolveNew=r),onRemoteRecords:r=>newHistory.push(r),onStatus:()=>{{}}}});
+(async()=>{{const oldFlush=oldTab.flush();const newFlush=newTab.flush();await Promise.resolve();
+resolveNew({{revision:2,records:{{new:'2026-08-11T09:00:00.000Z'}}}});await newFlush;
+resolveOld({{revision:1,records:{{old:'2026-08-10T09:00:00.000Z'}}}});await oldFlush;
+process.stdout.write(JSON.stringify({{oldHistory,newHistory}}));}})();
+"""
+    result = run_node(script)
+    assert result["oldHistory"][-1] == {"new": "2026-08-11T09:00:00.000Z"}
+    assert result["newHistory"][-1] == {"new": "2026-08-11T09:00:00.000Z"}
+
+
+def test_existing_browser_records_migrate_once_and_lifecycle_replays():
+    script = f"""
+const createLaterSync=require({json.dumps(str(LATER_SYNC))});
+const values=new Map(); const handlers={{}}; let sequence=0; const requests=[];
+const sync=createLaterSync({{
+ storage:{{getItem:k=>values.get(k)||null,setItem:(k,v)=>values.set(k,v),removeItem:k=>values.delete(k)}},
+ getLogin:()=> 'timmy',createOperationId:()=> 'migration-'+(++sequence),
+ fetchJson:async (_url,options={{}})=>{{requests.push(options.method||'GET');return {{revision:options.method?1:0,records:{{}}}}}},
+ onRemoteRecords:()=>{{}},onStatus:()=>{{}},
+}});
+const records={{'issue:r:1:':'2026-08-10T09:00:00.000Z'}};
+const first=sync.migrate(records),second=sync.migrate(records);
+sync.startLifecycle({{window:{{addEventListener:(n,h)=>handlers[n]=h}},document:{{hidden:false,addEventListener:()=>{{}}}}}});
+(async()=>{{await handlers.online();process.stdout.write(JSON.stringify({{first,second,requests,pending:sync.pending()}}));}})();
+"""
+    assert run_node(script) == {
+        "first": True,
+        "second": False,
+        "requests": ["PATCH"],
+        "pending": [],
+    }
+
+
+def test_later_work_emits_local_changes_adopts_remote_truth_and_retires_expiry():
+    script = f"""
+const createLaterWork=require({json.dumps(str(LATER_WORK))});
+const values=new Map(); const changes=[]; const expired=[];
+let clock=new Date('2026-08-08T12:00:00Z');
+const item={{kind:'issue',repository:'stackchain/api',number:17}};
+const work=createLaterWork({{
+ storage:{{getItem:k=>values.get(k)||null,setItem:(k,v)=>values.set(k,v),removeItem:k=>values.delete(k)}},
+ getLogin:()=> 'timmy',now:()=>clock,setTimer:()=>1,clearTimer:()=>{{}},
+ onChange:(action,id,wakeAt)=>changes.push([action,id,wakeAt]),
+ onExpire:ids=>expired.push(ids),
+}});
+work.defer(item,new Date('2026-08-08T16:00:00Z'));
+work.restore(item);
+work.adopt({{'issue:stackchain/api:17:':'2026-08-09T09:00:00.000Z'}});
+const remote=work.partition([item]);
+clock=new Date('2026-08-09T09:00:01Z');
+const awake=work.partition([item]);
+process.stdout.write(JSON.stringify({{changes,expired,remote:remote.later,awake:awake.active}}));
+"""
+    result = run_node(script)
+    assert result["changes"] == [
+        ["defer", "issue:stackchain/api:17:", "2026-08-08T16:00:00.000Z"],
+        ["restore", "issue:stackchain/api:17:", None],
+    ]
+    assert result["remote"][0]["deferred_until"] == "2026-08-09T09:00:00.000Z"
+    assert result["awake"] == [{"kind": "issue", "repository": "stackchain/api", "number": 17}]
+    assert result["expired"] == [["issue:stackchain/api:17:"]]
+
+
+@pytest.mark.anyio
+async def test_dashboard_syncs_every_later_change_and_exposes_account_status():
+    html = await dashboard()
+
+    assert '<script src="static/later-sync.js"></script>' in html
+    assert 'id="later-sync-status"' in html
+    assert "const laterSync = createLaterSync({" in html
+    assert "onRemoteRecords: records =>" in html
+    assert "onChange: (action, itemId, wakeAt) =>" in html
+    assert "onExpire: ids =>" in html
+    assert "laterSync.enqueue(action, itemId, wakeAt)" in html
+    assert "ids.map(id => laterSync.enqueue('restore', id)).every(Boolean)" in html
+    assert "laterSync.migrate(laterWork.read());" in html
+    assert "laterSync.flush();" in html
+    assert "Later saved to account." in html
+
+
+def test_later_sync_ships_atomically_in_the_offline_shell():
+    source = (Path(__file__).parents[1] / "frontend" / "service-worker.js").read_text()
+
+    assert "stackchain-dashboard-shell-v54" in source
+    assert "BASE + 'static/later-sync.js'" in source

tests/test_markdown_renderer.py

@@ -137,4 +137,4 @@ def test_markdown_work_bodies_are_mobile_safe_block_containers():
     assert ".markdown-content { min-width:0; max-width:100%; overflow-wrap:anywhere;" in css
     assert ".markdown-content pre { max-width:100%; overflow-x:auto;" in css
     assert ".markdown-content a { min-height:44px;" in css
-    assert "stackchain-dashboard-shell-v45" in worker
+    assert "stackchain-dashboard-shell-v54" in worker

tests/test_mobile_composer_integration.py

@@ -35,4 +35,4 @@ def test_offline_shell_contains_every_local_dashboard_runtime_asset():
     shell_assets = set(re.findall(r"BASE \+ '([^']+)'", worker.split("async function sessionCsrf", 1)[0]))
 
     assert local_assets <= shell_assets, f"Offline shell is missing: {sorted(local_assets - shell_assets)}"
-    assert "stackchain-dashboard-shell-v45" in worker
+    assert "stackchain-dashboard-shell-v54" in worker

tests/test_my_work.py

@@ -11,6 +11,7 @@ from tests.dashboard_bundle import dashboard
 MY_WORK = Path(__file__).parents[1] / "frontend" / "my-work.js"
 LATER_WORK = Path(__file__).parents[1] / "frontend" / "later-work.js"
 DETAIL_DEFER = Path(__file__).parents[1] / "frontend" / "detail-defer.js"
+LATER_PICKER = Path(__file__).parents[1] / "frontend" / "later-picker.js"
 REVIEW_SHEET = Path(__file__).parents[1] / "frontend" / "review-sheet.js"
 ISSUE_SHEET = Path(__file__).parents[1] / "frontend" / "issue-sheet.js"
 CREATE_ISSUE_SHEET = Path(__file__).parents[1] / "frontend" / "create-issue-sheet.js"
@@ -1176,6 +1177,29 @@ async def test_mobile_my_work_wires_touch_safe_non_mutating_later_actions():
     assert "'Deferred until ' + fmt(until)" in html
 
 
+@pytest.mark.anyio
+async def test_mobile_later_actions_open_one_keyboard_safe_exact_time_dialog():
+    html = await dashboard()
+
+    assert '<script src="static/later-picker.js"></script>' in html
+    assert html.count('<button type="button" data-detail-defer-custom') == 4
+    assert 'data-later-custom' in html
+    assert 'id="later-picker"' in html
+    assert 'role="dialog"' in html
+    assert 'type="datetime-local"' in html
+    assert 'id="later-picker-timezone"' in html
+    assert 'id="later-picker-error"' in html
+    assert 'createLaterPicker({' in html
+    assert "laterPicker.open(item, button, 'detail')" in html
+    assert "laterPicker.open(item, button, 'card')" in html
+    assert "detailDefer.deferUntil(item, until, {" in html
+    assert "laterWork.defer(item, until)" in html
+    assert "fetch(" not in LATER_PICKER.read_text()
+    assert '.later-picker-panel' in html
+    assert '.later-picker { box-sizing:border-box; width:100%; height:100%;' in html
+    assert 'env(safe-area-inset-bottom)' in html
+
+
 def test_milestone_lane_composes_with_type_filter_and_updates_confirmed_snapshot():
     payload = {
         "issues": [
@@ -1942,6 +1966,113 @@ Promise.all([capture.loadMilestones('stackchain/api'), capture.submit(capture.lo
     assert output["stored"]["number"] == 221
 
 
+def test_issue_capture_finds_only_open_issue_duplicates_in_the_selected_repository():
+    script = f"""
+const createIssueCapture = require({json.dumps(str(CREATE_ISSUE_SHEET))});
+const calls = [];
+const capture = createIssueCapture({{
+  storage: {{getItem:()=>null, setItem:()=>{{}}, removeItem:()=>{{}}}},
+  fetchJson: url => {{
+    calls.push(url);
+    return Promise.resolve({{items:[
+      {{kind:'issue', state:'open', repository:'stackchain/api', number:7, title:'Investigate checkout latency'}},
+      {{kind:'pull', state:'open', repository:'stackchain/api', number:8, title:'Investigate checkout latency'}},
+      {{kind:'issue', state:'closed', repository:'stackchain/api', number:9, title:'Investigate checkout latency'}},
+      {{kind:'issue', state:'open', repository:'stackchain/web', number:10, title:'Investigate checkout latency'}},
+      {{kind:'issue', state:'open', repository:'stackchain/api', number:11, title:'Checkout latency alert'}},
+      {{kind:'issue', state:'open', repository:'stackchain/api', number:12, title:'Checkout latency follow-up'}},
+      {{kind:'issue', state:'open', repository:'stackchain/api', number:13, title:'Fourth match is bounded'}},
+    ]}});
+  }},
+}});
+capture.findDuplicates({{repository:'stackchain/api', title:'  Investigate checkout latency  '}}).then(state =>
+  process.stdout.write(JSON.stringify({{calls, state}}))
+);
+"""
+    result = subprocess.run(
+        ["node", "-e", script], check=True, capture_output=True, text=True
+    )
+    output = json.loads(result.stdout)
+
+    assert output["calls"] == [
+        "api/v1/search?q=Investigate%20checkout%20latency&limit=10"
+    ]
+    assert output["state"]["status"] == "ready"
+    assert [item["number"] for item in output["state"]["candidates"]] == [7, 11, 12]
+
+
+def test_issue_capture_ignores_stale_duplicate_results_and_resets_create_anyway_acknowledgement():
+    script = f"""
+const createIssueCapture = require({json.dumps(str(CREATE_ISSUE_SHEET))});
+const pending = [];
+const capture = createIssueCapture({{
+  storage: {{getItem:()=>null, setItem:()=>{{}}, removeItem:()=>{{}}}},
+  fetchJson: url => new Promise((resolve, reject) => pending.push({{url, resolve, reject}})),
+}});
+const firstDraft = {{repository:'stackchain/api', title:'Checkout latency'}};
+const latestDraft = {{repository:'stackchain/api', title:'Checkout latency alert'}};
+const first = capture.findDuplicates(firstDraft);
+const latest = capture.findDuplicates(latestDraft);
+pending[1].resolve({{items:[{{kind:'issue',state:'open',repository:'stackchain/api',number:22,title:'Checkout latency alert'}}]}});
+latest.then(latestState => {{
+  const blocked = capture.needsDuplicateAcknowledgement(latestDraft);
+  capture.acknowledgeDuplicates(latestDraft);
+  const allowed = capture.needsDuplicateAcknowledgement(latestDraft);
+  const changedDraft = {{...latestDraft,title:'Checkout latency alert today'}};
+  const changedSearch = capture.findDuplicates(changedDraft);
+  pending[2].resolve({{items:[{{kind:'issue',state:'open',repository:'stackchain/api',number:23,title:'Checkout latency alert today'}}]}});
+  changedSearch.then(() => {{
+    const changed = capture.needsDuplicateAcknowledgement(changedDraft);
+    pending[0].resolve({{items:[{{kind:'issue',state:'open',repository:'stackchain/api',number:21,title:'Old result'}}]}});
+    first.then(staleState => {{
+      const failure = capture.findDuplicates({{repository:'stackchain/api',title:'Network failure'}});
+      pending[3].reject(new Error('offline'));
+      failure.then(failedState => process.stdout.write(JSON.stringify({{
+        latestState, staleState, blocked, allowed, changed, failedState,
+        failureBlocks:capture.needsDuplicateAcknowledgement({{repository:'stackchain/api',title:'Network failure'}}),
+      }})));
+    }});
+  }});
+}});
+"""
+    result = subprocess.run(
+        ["node", "-e", script], check=True, capture_output=True, text=True
+    )
+    output = json.loads(result.stdout)
+
+    assert output["latestState"]["status"] == "ready"
+    assert output["staleState"]["status"] == "stale"
+    assert output["blocked"] is True
+    assert output["allowed"] is False
+    assert output["changed"] is True
+    assert output["failedState"]["status"] == "failed"
+    assert output["failureBlocks"] is False
+
+
+def test_issue_capture_keeps_partial_duplicate_search_advisory():
+    script = f"""
+const createIssueCapture = require({json.dumps(str(CREATE_ISSUE_SHEET))});
+const draft = {{repository:'stackchain/api', title:'Checkout latency'}};
+const capture = createIssueCapture({{
+  storage: {{getItem:()=>null, setItem:()=>{{}}, removeItem:()=>{{}}}},
+  fetchJson: () => Promise.resolve({{partial:true, items:[
+    {{kind:'issue',state:'open',repository:'stackchain/api',number:24,title:'Checkout latency'}},
+  ]}}),
+}});
+capture.findDuplicates(draft).then(state => process.stdout.write(JSON.stringify({{
+  state, blocked:capture.needsDuplicateAcknowledgement(draft),
+}})));
+"""
+    result = subprocess.run(
+        ["node", "-e", script], check=True, capture_output=True, text=True
+    )
+    output = json.loads(result.stdout)
+
+    assert output["state"]["partial"] is True
+    assert [item["number"] for item in output["state"]["candidates"]] == [24]
+    assert output["blocked"] is False
+
+
 def test_unread_updates_enrich_matching_work_and_keep_unassigned_mentions_actionable():
     payload = {
         "user": {"login": "timmy"},
@@ -3124,6 +3255,25 @@ async def test_mobile_my_work_captures_new_issue_in_accessible_draft_safe_sheet(
     assert '.create-issue-label-option' in html and 'min-height:44px' in html
 
 
+@pytest.mark.anyio
+async def test_mobile_issue_capture_warns_before_queuing_a_possible_duplicate():
+    html = await dashboard()
+
+    assert 'id="create-issue-duplicates"' in html
+    assert 'id="create-issue-duplicate-list"' in html
+    assert 'aria-live="polite"' in html
+    assert 'id="create-issue-anyway"' in html and 'Create anyway' in html
+    assert "issueCapture.findDuplicates(draft)" in html
+    assert "issueCapture.needsDuplicateAcknowledgement(captureDraft)" in html
+    assert "issueCapture.acknowledgeDuplicates(captureDraft)" in html
+    assert html.index("issueCapture.needsDuplicateAcknowledgement(captureDraft)") < html.index(
+        "issueOutbox.enqueueDurably(captureDraft)"
+    )
+    assert ".create-issue-duplicate-card" in html
+    assert ".create-issue-duplicate-card a" in html and "min-height:44px" in html
+    assert "overflow-wrap:anywhere" in html
+
+
 @pytest.mark.anyio
 async def test_mobile_dashboard_puts_filterable_my_work_before_auxiliary_panels():
     html = await dashboard()

tests/test_outbox_coordinator.py

@@ -110,13 +110,15 @@ const seen=[];
 const unsubscribe=second.subscribe(change=>seen.push(change));
 first.notify('issue');
 first.notify('authored');
+first.notify('today');
+first.notify('later');
 unsubscribe();
 first.notify('issue');
 process.stdout.write(JSON.stringify({{seen,signal:JSON.parse(storage.getItem('stackchain.outbox-change.v1'))}}));
 """
     output = run_node(script)
 
-    assert [change["queue"] for change in output["seen"]] == ["issue", "authored"]
+    assert [change["queue"] for change in output["seen"]] == ["issue", "authored", "today", "later"]
     assert output["signal"]["queue"] == "issue"
     assert output["signal"]["tabId"] == "first"
 

tests/test_readme.py

@@ -34,6 +34,14 @@ def test_readme_documents_liveness_and_gitea_readiness_checks():
     assert "HTTP 503" in text
 
 
+def test_readme_documents_exact_later_return_times():
+    text = " ".join(README.read_text().split())
+
+    assert "Choose date & time" in text
+    assert "valid future local date and time" in text
+    assert "exact instant" in text
+
+
 def test_readme_documents_bounded_offline_today_details_and_safe_actions():
     text = " ".join(README.read_text().split())
 

tests/test_service_worker.py

@@ -105,26 +105,48 @@ async function dispatchNotificationClick(route) {{
     return json.loads(completed.stdout)
 
 
+def test_duplicate_aware_capture_ships_in_a_new_offline_shell():
+    source = WORKER.read_text()
+
+    assert "stackchain-dashboard-shell-v54" in source
+    assert "BASE + 'static/create-issue-sheet.js'" in source
+    assert "BASE + 'static/dashboard.js'" in source
+
+
+def test_exact_later_picker_ships_atomically_in_a_new_offline_shell():
+    source = WORKER.read_text()
+
+    assert "stackchain-dashboard-shell-v54" in source
+    assert "BASE + 'static/later-picker.js'" in source
+
+
 def test_navigation_deadline_ships_in_a_new_shell_cache():
     source = WORKER.read_text()
 
-    assert "stackchain-dashboard-shell-v45" in source
+    assert "stackchain-dashboard-shell-v54" in source
     assert "BASE + 'static/dashboard.css'" in source
     assert "BASE + 'static/dashboard.js'" in source
     assert "BASE + 'static/install-app.js'" in source
 
 
+def test_today_convergence_ships_in_a_new_shell_cache():
+    source = WORKER.read_text()
+
+    assert "stackchain-dashboard-shell-v54" in source
+    assert "BASE + 'static/today-sync.js'" in source
+
+
 def test_mobile_search_viewport_ships_in_a_new_offline_shell():
     source = WORKER.read_text()
 
-    assert "stackchain-dashboard-shell-v45" in source
+    assert "stackchain-dashboard-shell-v54" in source
     assert "BASE + 'static/mobile-search-viewport.js'" in source
 
 
 def test_update_ownership_flow_ships_atomically_in_a_new_offline_shell():
     source = WORKER.read_text()
 
-    assert "stackchain-dashboard-shell-v45" in source
+    assert "stackchain-dashboard-shell-v54" in source
     assert "BASE + 'static/update-ownership.js'" in source
 
 
@@ -322,7 +344,9 @@ def test_install_precaches_complete_subpath_scoped_app_shell():
         "/dashboard/static/today-sync.js",
         "/dashboard/static/update-ownership.js",
         "/dashboard/static/later-work.js",
+        "/dashboard/static/later-sync.js",
         "/dashboard/static/detail-defer.js",
+        "/dashboard/static/later-picker.js",
         "/dashboard/static/pick-work.js",
         "/dashboard/static/conversation.js",
         "/dashboard/static/issue-sheet.js",

tests/test_today_store.py

@@ -1,3 +1,5 @@
+import sqlite3
+
 import pytest
 import httpx
 
@@ -5,6 +7,28 @@ from src import main
 from src.today_store import TodayPlanFull, TodayStore
 
 
+@pytest.mark.anyio
+async def test_transient_today_store_failure_tells_clients_when_to_retry(monkeypatch):
+    async def user():
+        return {"login": "timmy"}
+
+    class BusyStore:
+        def apply(self, *_args, **_kwargs):
+            raise sqlite3.OperationalError("database is locked")
+
+    monkeypatch.setattr(main, "current_user", user)
+    monkeypatch.setattr(main, "_today_store", lambda: BusyStore())
+    payload = main.TodayOperation(
+        operation_id="retry-me", action="add", item_id="issue:r:1:"
+    )
+
+    with pytest.raises(main.HTTPException) as raised:
+        await main.update_today_plan(payload)
+
+    assert raised.value.status_code == 503
+    assert raised.value.headers == {"Retry-After": "1"}
+
+
 def test_operations_are_durable_ordered_idempotent_and_account_scoped(tmp_path):
     path = tmp_path / "today.sqlite3"
     store = TodayStore(path, limit=3)
@@ -53,6 +77,36 @@ def test_limit_is_atomic_and_remove_frees_capacity(tmp_path):
     ]
 
 
+def test_batch_applies_ordered_operations_once_and_rejects_only_capacity_conflicts(tmp_path):
+    store = TodayStore(tmp_path / "today.sqlite3", limit=2)
+
+    result = store.apply_batch(
+        "timmy",
+        [
+            {"operation_id": "one", "action": "add", "item_id": "issue:r:1:"},
+            {"operation_id": "two", "action": "add", "item_id": "issue:r:2:"},
+            {"operation_id": "full", "action": "add", "item_id": "issue:r:3:"},
+            {"operation_id": "remove", "action": "remove", "item_id": "issue:r:1:"},
+            {"operation_id": "three", "action": "add", "item_id": "issue:r:3:"},
+        ],
+    )
+
+    assert result == {
+        "revision": 4,
+        "ids": ["issue:r:2:", "issue:r:3:"],
+        "accepted_operation_ids": ["one", "two", "remove", "three"],
+        "duplicate_operation_ids": [],
+        "rejected_operations": [{"operation_id": "full", "reason": "today_full"}],
+    }
+    replay = store.apply_batch("timmy", [
+        {"operation_id": "two", "action": "add", "item_id": "issue:r:2:"},
+        {"operation_id": "three", "action": "add", "item_id": "issue:r:3:"},
+    ])
+    assert replay["revision"] == 4
+    assert replay["accepted_operation_ids"] == []
+    assert replay["duplicate_operation_ids"] == ["two", "three"]
+
+
 @pytest.mark.anyio
 async def test_authenticated_today_api_uses_confirmed_account_and_csrf(monkeypatch, tmp_path):
     monkeypatch.setenv("STACKCHAIN_DASHBOARD_AUTH_MODE", "operator")
@@ -85,9 +139,10 @@ async def test_authenticated_today_api_uses_confirmed_account_and_csrf(monkeypat
         changed = await client.patch(
             "/api/v1/today",
             json={
-                "operation_id": "mobile-1",
-                "action": "add",
-                "item_id": "issue:stackchain/dashboard:357:",
+                "operations": [
+                    {"operation_id": "mobile-1", "action": "add", "item_id": "issue:stackchain/dashboard:357:"},
+                    {"operation_id": "mobile-2", "action": "add", "item_id": "issue:stackchain/dashboard:359:"},
+                ],
             },
             headers={
                 "Origin": "https://test",
@@ -98,8 +153,12 @@ async def test_authenticated_today_api_uses_confirmed_account_and_csrf(monkeypat
 
     assert forbidden.status_code == 403
     assert changed.status_code == 200
-    assert changed.json() == fetched.json() == {
-        "revision": 1,
-        "ids": ["issue:stackchain/dashboard:357:"],
+    assert changed.json() == {
+        "revision": 2,
+        "ids": ["issue:stackchain/dashboard:357:", "issue:stackchain/dashboard:359:"],
+        "accepted_operation_ids": ["mobile-1", "mobile-2"],
+        "duplicate_operation_ids": [],
+        "rejected_operations": [],
     }
+    assert fetched.json() == {"revision": 2, "ids": ["issue:stackchain/dashboard:357:", "issue:stackchain/dashboard:359:"]}
     assert fetched.headers["cache-control"] == "no-store"

tests/test_today_sync.py

@@ -4,6 +4,90 @@ from pathlib import Path
 
 
 TODAY_SYNC = Path(__file__).parents[1] / "frontend" / "today-sync.js"
+COORDINATOR = Path(__file__).parents[1] / "frontend" / "outbox-coordinator.js"
+
+
+def test_two_tabs_cannot_erase_each_others_today_edits_or_double_drain():
+    script = f"""
+const createTodaySync = require({json.dumps(str(TODAY_SYNC))});
+const createCoordinator = require({json.dumps(str(COORDINATOR))});
+const values = new Map();
+const storage = {{get length(){{return values.size}},key:i=>[...values.keys()][i]||null,
+ getItem:k=>values.get(k)||null,setItem:(k,v)=>values.set(k,v),removeItem:k=>values.delete(k)}};
+const channels=[]; const channelFactory=()=>{{const channel={{onmessage:null,postMessage:data=>channels.filter(x=>x!==channel).forEach(x=>x.onmessage?.({{data}})),close(){{}}}};channels.push(channel);return channel}};
+const held=new Set(); const locks={{request:async(name,_options,work)=>{{if(held.has(name))return work(null);held.add(name);try{{return await work({{name}})}}finally{{held.delete(name)}}}}}};
+let sequence=0,releaseFirst;const delivered=[];
+const make=tab=>createTodaySync({{storage,getLogin:()=> 'timmy',createOperationId:()=>tab+'-'+(++sequence),coordinator:createCoordinator({{storage,locks,channelFactory,tabId:tab}}),
+ fetchJson:async(_url,options={{}})=>{{if(!options.method)return {{revision:0,ids:[]}};const operation=JSON.parse(options.body).operations[0];delivered.push(operation.operation_id);if(delivered.length===1)await new Promise(resolve=>releaseFirst=resolve);return {{revision:delivered.length,ids:delivered}}}},onRemoteIds:()=>{{}},onStatus:()=>{{}}}});
+const first=make('first'),second=make('second');first.enqueue('add','issue:r:1:');
+(async()=>{{const draining=first.flush();while(!releaseFirst)await Promise.resolve();second.enqueue('add','issue:r:2:');const competing=second.flush();releaseFirst();await Promise.all([draining,competing]);await first.flush();process.stdout.write(JSON.stringify({{delivered,pending:first.pending(),keys:[...values.keys()]}}));}})();
+"""
+    result = json.loads(subprocess.run(["node", "-e", script], check=True, capture_output=True, text=True).stdout)
+    assert sorted(result["delivered"]) == ["first-1", "second-2"]
+    assert len(result["delivered"]) == 2
+    assert result["pending"] == []
+    assert not any(".operation." in key for key in result["keys"])
+
+
+def test_operations_enqueued_during_an_inflight_flush_are_drained_before_it_settles():
+    script = f"""
+const createTodaySync = require({json.dumps(str(TODAY_SYNC))});
+const values = new Map();
+const patches = [];
+let sequence = 0;
+let releaseFirstPatch;
+const firstPatchBlocked = new Promise(resolve => {{ globalThis.firstPatchStarted = resolve; }});
+const sync = createTodaySync({{
+  storage: {{getItem:k=>values.get(k)||null,setItem:(k,v)=>values.set(k,v),removeItem:k=>values.delete(k)}},
+  getLogin: () => 'timmy', createOperationId: () => 'op-' + (++sequence),
+  fetchJson: async (_url, options={{}}) => {{
+    if (!options.method) return {{revision:0, ids:[]}};
+    const operation = JSON.parse(options.body).operations[0];
+    patches.push(operation);
+    if (patches.length === 1) {{
+      globalThis.firstPatchStarted();
+      await new Promise(resolve => {{ releaseFirstPatch = resolve; }});
+    }}
+    return {{revision:patches.length, ids:patches.map(item => item.item_id)}};
+  }},
+  onRemoteIds: ids => {{ globalThis.ids = ids; }},
+  onStatus: status => {{ globalThis.status = status; }},
+}});
+sync.enqueue('add', 'issue:r:1:');
+(async () => {{
+  const firstFlush = sync.flush();
+  await firstPatchBlocked;
+  sync.enqueue('add', 'issue:r:2:');
+  const sharedFlush = sync.flush();
+  const sharesInflight = firstFlush === sharedFlush;
+  releaseFirstPatch();
+  await sharedFlush;
+  process.stdout.write(JSON.stringify({{
+    sharesInflight, patches, pending:sync.pending(), ids:globalThis.ids, status:globalThis.status,
+  }}));
+}})();
+"""
+    result = json.loads(
+        subprocess.run(["node", "-e", script], check=True, capture_output=True, text=True).stdout
+    )
+
+    assert result == {
+        "sharesInflight": True,
+        "patches": [
+            {"operation_id": "op-1", "action": "add", "item_id": "issue:r:1:", "direction": None},
+            {"operation_id": "op-2", "action": "add", "item_id": "issue:r:2:", "direction": None},
+        ],
+        "pending": [],
+        "ids": ["issue:r:1:", "issue:r:2:"],
+        "status": "saved",
+    }
+
+
+def test_inflight_today_drain_ships_in_a_new_offline_shell():
+    source = (Path(__file__).parents[1] / "frontend" / "service-worker.js").read_text()
+
+    assert "stackchain-dashboard-shell-v54" in source
+    assert "BASE + 'static/today-sync.js'" in source
 
 
 def test_local_operations_replay_once_then_adopt_server_order():
@@ -24,7 +108,7 @@ const sync = createTodaySync({{
   fetchJson: async (url, options={{}}) => {{
     requests.push({{url, body: options.body && JSON.parse(options.body)}});
     if (!options.method) return remote;
-    remote = {{revision: remote.revision + 1, ids:['issue:r:9:', options.body && JSON.parse(options.body).item_id]}};
+    remote = {{revision: remote.revision + 1, ids:['issue:r:9:', JSON.parse(options.body).operations[0].item_id]}};
     return remote;
   }},
   onRemoteIds: ids => {{ globalThis.adopted = ids; }},
@@ -47,19 +131,37 @@ sync.enqueue('add', 'issue:r:2:');
     assert [request["url"] for request in result["requests"]] == [
         "api/v1/today",
         "api/v1/today",
-        "api/v1/today",
     ]
-    assert result["requests"][1]["body"] == {
+    assert result["requests"][0]["body"] == {"operations": [{
         "operation_id": "fixed-op",
         "action": "add",
         "item_id": "issue:r:2:",
         "direction": None,
-    }
+    }]}
     assert result["adopted"] == ["issue:r:9:", "issue:r:2:"]
     assert result["status"] == "saved"
     assert result["pending"] == []
 
 
+def test_pending_today_edits_are_sent_as_one_batch_without_a_preflight_get():
+    script = f"""
+const createTodaySync = require({json.dumps(str(TODAY_SYNC))});
+const values = new Map(); const requests=[]; let sequence=0;
+const sync=createTodaySync({{
+ storage:{{getItem:k=>values.get(k)||null,setItem:(k,v)=>values.set(k,v),removeItem:k=>values.delete(k)}},
+ getLogin:()=> 'timmy',createOperationId:()=> 'op-'+(++sequence),
+ fetchJson:async (_url,options={{}})=>{{const body=JSON.parse(options.body);requests.push(body);return {{revision:2,ids:['issue:r:1:','issue:r:2:'],accepted_operation_ids:body.operations.map(x=>x.operation_id),duplicate_operation_ids:[],rejected_operations:[]}}}},
+ onRemoteIds:()=>{{}},onStatus:()=>{{}},
+}});
+sync.enqueue('add','issue:r:1:');sync.enqueue('add','issue:r:2:');
+(async()=>{{await sync.flush();process.stdout.write(JSON.stringify({{requests,pending:sync.pending()}}));}})();
+"""
+    result = json.loads(subprocess.run(["node", "-e", script], check=True, capture_output=True, text=True).stdout)
+    assert len(result["requests"]) == 1
+    assert [item["operation_id"] for item in result["requests"][0]["operations"]] == ["op-1", "op-2"]
+    assert result["pending"] == []
+
+
 def test_failed_delivery_stays_pending_for_offline_replay():
     script = f"""
 const createTodaySync = require({json.dumps(str(TODAY_SYNC))});
@@ -83,7 +185,77 @@ sync.enqueue('move', 'issue:r:2:', 'up');
             "item_id": "issue:r:2:",
             "direction": "up",
         }],
-        "status": "pending",
+        "status": "retrying",
+    }
+
+
+def test_retryable_failure_replays_automatically_once_with_same_operation_id():
+    script = f"""
+const createTodaySync = require({json.dumps(str(TODAY_SYNC))});
+const values = new Map(); const timers = []; const statuses = []; const patches = [];
+let attempts = 0;
+const sync = createTodaySync({{
+  storage: {{getItem:k=>values.get(k)||null,setItem:(k,v)=>values.set(k,v),removeItem:k=>values.delete(k)}},
+  getLogin:()=> 'timmy', createOperationId:()=> 'stable-op',
+  setTimer:(callback,delay)=>{{timers.push({{callback,delay}});return timers.length}}, clearTimer:()=>{{}},
+  fetchJson:async (_url,options={{}})=>{{
+    attempts += 1;
+    if (attempts === 1) {{ const error = new Error('busy'); error.status=503; error.retryAfter=2; throw error; }}
+    if (options.method) patches.push(...JSON.parse(options.body).operations);
+    return options.method ? {{revision:1,ids:['issue:r:2:']}} : {{revision:0,ids:[]}};
+  }},
+  onRemoteIds:()=>{{}}, onStatus:(state,detail)=>statuses.push([state,detail?.delayMs||null]),
+}});
+sync.enqueue('add','issue:r:2:');
+(async()=>{{
+  await sync.flush();
+  const scheduled = timers.map(timer=>timer.delay);
+  await timers[0].callback();
+  process.stdout.write(JSON.stringify({{scheduled,attempts,patches,pending:sync.pending(),statuses}}));
+}})();
+"""
+    result = json.loads(
+        subprocess.run(["node", "-e", script], check=True, capture_output=True, text=True).stdout
+    )
+
+    assert result["scheduled"] == [2000]
+    assert result["attempts"] == 2
+    assert result["patches"] == [{
+        "operation_id": "stable-op", "action": "add", "item_id": "issue:r:2:", "direction": None,
+    }]
+    assert result["pending"] == []
+    assert ["retrying", 2000] in result["statuses"]
+    assert result["statuses"][-1] == ["saved", None]
+
+
+def test_duplicate_pending_retirements_collapse_to_one_effective_remove():
+    script = f"""
+const createTodaySync = require({json.dumps(str(TODAY_SYNC))});
+const values = new Map();
+let sequence = 0;
+const statuses = [];
+const sync = createTodaySync({{
+  storage: {{getItem:k=>values.get(k)||null,setItem:(k,v)=>values.set(k,v),removeItem:k=>values.delete(k)}},
+  getLogin: () => 'timmy', createOperationId: () => 'remove-' + (++sequence),
+  fetchJson: async () => ({{revision:0,ids:[]}}), onRemoteIds:()=>{{}}, onStatus:value=>statuses.push(value),
+}});
+const first = sync.enqueue('remove', 'issue:r:1:');
+const duplicate = sync.enqueue('remove', 'issue:r:1:');
+process.stdout.write(JSON.stringify({{first, duplicate, pending:sync.pending(), statuses}}));
+"""
+    result = json.loads(
+        subprocess.run(["node", "-e", script], check=True, capture_output=True, text=True).stdout
+    )
+    assert result == {
+        "first": True,
+        "duplicate": True,
+        "pending": [{
+            "operation_id": "remove-1",
+            "action": "remove",
+            "item_id": "issue:r:1:",
+            "direction": None,
+        }],
+        "statuses": ["pending", "pending"],
     }
 
 
@@ -123,8 +295,8 @@ const sync = createTodaySync({{
   storage: {{getItem:k=>values.get(k)||null,setItem:(k,v)=>values.set(k,v),removeItem:k=>values.delete(k)}},
   getLogin: () => 'timmy', createOperationId: () => 'sixth',
   fetchJson: async (_url, options={{}}) => {{
-    if (options.method) {{ patch = true; const error = new Error('full'); error.status = 409; throw error; }}
-    return {{revision:5, ids:['1','2','3','4','5']}};
+    patch = true;
+    return {{revision:5, ids:['1','2','3','4','5'], accepted_operation_ids:[], duplicate_operation_ids:[], rejected_operations:[{{operation_id:'sixth',reason:'today_full'}}]}};
   }},
   onRemoteIds:ids=>{{globalThis.ids=ids}}, onStatus:value=>{{globalThis.status=value}},
 }});
@@ -140,3 +312,180 @@ sync.enqueue('add', '6');
         "ids": ["1", "2", "3", "4", "5"],
         "status": "full",
     }
+
+
+def test_server_limit_conflict_drops_only_the_rejected_operation_and_drains_later_edits():
+    script = f"""
+const createTodaySync = require({json.dumps(str(TODAY_SYNC))});
+const values = new Map();
+const patches = [];
+let sequence = 0;
+const statuses = [];
+const sync = createTodaySync({{
+  storage: {{getItem:k=>values.get(k)||null,setItem:(k,v)=>values.set(k,v),removeItem:k=>values.delete(k)}},
+  getLogin: () => 'timmy', createOperationId: () => 'op-' + (++sequence),
+  fetchJson: async (_url, options={{}}) => {{
+    const operations = JSON.parse(options.body).operations;
+    patches.push(...operations);
+    return {{revision:6, ids:['1','2','3','4'], accepted_operation_ids:['op-2'], duplicate_operation_ids:[], rejected_operations:[{{operation_id:'op-1',reason:'today_full'}}]}};
+  }},
+  onRemoteIds: ids => {{ globalThis.ids = ids; }},
+  onStatus: status => statuses.push(status),
+}});
+sync.enqueue('add', '6');
+sync.enqueue('remove', '5');
+(async()=>{{
+  const result = await sync.flush();
+  process.stdout.write(JSON.stringify({{result, patches, pending:sync.pending(), ids:globalThis.ids, statuses}}));
+}})();
+"""
+    result = json.loads(
+        subprocess.run(["node", "-e", script], check=True, capture_output=True, text=True).stdout
+    )
+
+    assert result == {
+        "result": False,
+        "patches": [
+            {"operation_id": "op-1", "action": "add", "item_id": "6", "direction": None},
+            {"operation_id": "op-2", "action": "remove", "item_id": "5", "direction": None},
+        ],
+        "pending": [],
+        "ids": ["1", "2", "3", "4"],
+        "statuses": ["pending", "pending", "full"],
+    }
+
+
+def test_tabs_ignore_an_older_response_after_a_newer_revision_is_broadcast():
+    script = f"""
+const createTodaySync = require({json.dumps(str(TODAY_SYNC))});
+const values = new Map();
+const storage = {{getItem:k=>values.get(k)||null,setItem:(k,v)=>values.set(k,v),removeItem:k=>values.delete(k)}};
+const listeners = [];
+const createChannel = () => ({{
+  addEventListener: (_name, listener) => listeners.push(listener),
+  postMessage: data => listeners.forEach(listener => listener({{data}})),
+}});
+let resolveOld;
+let resolveNew;
+const oldHistory = [];
+const newHistory = [];
+const oldTab = createTodaySync({{
+  storage, getLogin:()=> 'timmy', createChannel,
+  fetchJson:()=>new Promise(resolve=>{{resolveOld=resolve}}),
+  onRemoteIds:ids=>oldHistory.push(ids), onStatus:()=>{{}},
+}});
+const newTab = createTodaySync({{
+  storage, getLogin:()=> 'timmy', createChannel,
+  fetchJson:()=>new Promise(resolve=>{{resolveNew=resolve}}),
+  onRemoteIds:ids=>newHistory.push(ids), onStatus:()=>{{}},
+}});
+(async()=>{{
+  const oldFlush = oldTab.flush();
+  const newFlush = newTab.flush();
+  await Promise.resolve();
+  resolveNew({{revision:2,ids:['new']}});
+  await newFlush;
+  resolveOld({{revision:1,ids:['old']}});
+  await oldFlush;
+  process.stdout.write(JSON.stringify({{oldHistory,newHistory}}));
+}})();
+"""
+    result = json.loads(
+        subprocess.run(["node", "-e", script], check=True, capture_output=True, text=True).stdout
+    )
+
+    assert result["oldHistory"][-1] == ["new"]
+    assert result["newHistory"][-1] == ["new"]
+
+
+def test_returning_online_replays_pending_operations():
+    script = f"""
+const createTodaySync = require({json.dumps(str(TODAY_SYNC))});
+const values = new Map();
+const handlers = {{}};
+const requests = [];
+let revision = 1;
+const sync = createTodaySync({{
+  storage: {{getItem:k=>values.get(k)||null,setItem:(k,v)=>values.set(k,v),removeItem:k=>values.delete(k)}},
+  getLogin:()=> 'timmy', createOperationId:()=> 'offline-add',
+  fetchJson:async (_url, options={{}})=>{{
+    requests.push(options.method || 'GET');
+    if (options.method) return {{revision:++revision,ids:['issue:r:1:']}};
+    return {{revision,ids:[]}};
+  }},
+  onRemoteIds:()=>{{}}, onStatus:()=>{{}},
+}});
+sync.enqueue('add', 'issue:r:1:');
+sync.startLifecycle({{
+  window: {{addEventListener:(name, handler)=>{{handlers[name]=handler}}}},
+  document: {{addEventListener:()=>{{}}, hidden:false}},
+}});
+(async()=>{{
+  await handlers.online();
+  process.stdout.write(JSON.stringify({{requests,pending:sync.pending()}}));
+}})();
+"""
+    result = json.loads(
+        subprocess.run(["node", "-e", script], check=True, capture_output=True, text=True).stdout
+    )
+
+    assert result == {"requests": ["PATCH"], "pending": []}
+
+
+def test_foregrounding_a_stale_tab_refreshes_the_saved_plan():
+    script = f"""
+const createTodaySync = require({json.dumps(str(TODAY_SYNC))});
+const handlers = {{}};
+const adopted = [];
+const documentObject = {{
+  hidden:true,
+  addEventListener:(name, handler)=>{{handlers[name]=handler}},
+}};
+const sync = createTodaySync({{
+  storage: {{getItem:()=>null,setItem:()=>{{}},removeItem:()=>{{}}}},
+  getLogin:()=> 'timmy',
+  fetchJson:async ()=>({{revision:7,ids:['issue:r:7:']}}),
+  onRemoteIds:ids=>adopted.push(ids), onStatus:()=>{{}},
+}});
+sync.startLifecycle({{
+  window: {{addEventListener:()=>{{}}}}, document:documentObject,
+}});
+(async()=>{{
+  await handlers.visibilitychange();
+  documentObject.hidden = false;
+  await handlers.visibilitychange();
+  process.stdout.write(JSON.stringify(adopted));
+}})();
+"""
+    result = json.loads(
+        subprocess.run(["node", "-e", script], check=True, capture_output=True, text=True).stdout
+    )
+
+    assert result == [["issue:r:7:"]]
+
+
+def test_old_account_broadcasts_are_ignored_after_identity_changes():
+    script = f"""
+const createTodaySync = require({json.dumps(str(TODAY_SYNC))});
+let login = 'timmy';
+let listener;
+const adopted = [];
+const sync = createTodaySync({{
+  storage: {{getItem:()=>null,setItem:()=>{{}},removeItem:()=>{{}}}},
+  getLogin:()=>login,
+  createChannel:()=>({{addEventListener:(_name, handler)=>{{listener=handler}},postMessage:()=>{{}},close:()=>{{}}}}),
+  fetchJson:async ()=>({{revision:1,ids:['timmy-plan']}}),
+  onRemoteIds:ids=>adopted.push(ids), onStatus:()=>{{}},
+}});
+(async()=>{{
+  await sync.flush();
+  login = 'alexander';
+  listener({{data:{{revision:2,ids:['timmy-secret']}}}});
+  process.stdout.write(JSON.stringify(adopted));
+}})();
+"""
+    result = json.loads(
+        subprocess.run(["node", "-e", script], check=True, capture_output=True, text=True).stdout
+    )
+
+    assert result == [["timmy-plan"]]

tests/test_today_work.py

@@ -16,6 +16,15 @@ def run_node(script):
     ).stdout
 
 
+@pytest.mark.anyio
+async def test_dashboard_surfaces_automatic_planning_retry_guidance():
+    html = await dashboard()
+
+    assert "error.retryAfter = retryAfter === null ? undefined : Number(retryAfter)" in html
+    assert "Today saved on this device · retrying" in html
+    assert "Later saved on this device · retrying" in html
+
+
 def test_today_queue_is_account_scoped_ordered_unique_and_bounded():
     script = f"""
 const createTodayWork = require({json.dumps(str(TODAY_WORK))});
@@ -78,6 +87,55 @@ process.stdout.write(JSON.stringify([
     ]
 
 
+def test_authoritative_reconciliation_reports_retired_ids_before_local_prune():
+    script = f"""
+const createTodayWork = require({json.dumps(str(TODAY_WORK))});
+const values = new Map();
+const storage = {{getItem:k=>values.get(k)||null,setItem:(k,v)=>values.set(k,v),removeItem:k=>values.delete(k)}};
+const queue = createTodayWork({{storage, getLogin: () => 'timmy'}});
+const item = number => ({{kind:'issue', repository:'r', number}});
+queue.add(item(1));
+queue.add(item(2));
+const reports = [];
+const visible = queue.reconcile([item(2)], {{
+  pruneMissing: true,
+  onPrune: retiredIds => reports.push({{retiredIds, idsDuringReport: queue.read()}}),
+}});
+queue.reconcile([item(2)], {{
+  pruneMissing: true,
+  onPrune: retiredIds => reports.push({{retiredIds, idsDuringReport: queue.read()}}),
+}});
+process.stdout.write(JSON.stringify({{reports, visible:visible.map(entry => entry.number), stored:queue.read()}}));
+"""
+
+    assert json.loads(run_node(script)) == {
+        "reports": [{
+            "retiredIds": ["issue:r:1:"],
+            "idsDuringReport": ["issue:r:1:", "issue:r:2:"],
+        }],
+        "visible": [2],
+        "stored": ["issue:r:2:"],
+    }
+
+
+def test_failed_retirement_queue_keeps_local_identity_for_retry():
+    script = f"""
+const createTodayWork = require({json.dumps(str(TODAY_WORK))});
+const values = new Map();
+const storage = {{getItem:k=>values.get(k)||null,setItem:(k,v)=>values.set(k,v),removeItem:k=>values.delete(k)}};
+const queue = createTodayWork({{storage, getLogin: () => 'timmy'}});
+const item = number => ({{kind:'issue', repository:'r', number}});
+queue.add(item(1));
+const visible = queue.reconcile([], {{pruneMissing:true, onPrune:() => false}});
+process.stdout.write(JSON.stringify({{visible, stored:queue.read()}}));
+"""
+
+    assert json.loads(run_node(script)) == {
+        "visible": [],
+        "stored": ["issue:r:1:"],
+    }
+
+
 def test_today_queue_adopts_bounded_server_order():
     script = f"""
 const createTodayWork = require({json.dumps(str(TODAY_WORK))});
@@ -115,16 +173,28 @@ async def test_dashboard_runs_the_curated_today_queue_as_a_mobile_work_flow():
     assert "todaySync.enqueue('add'" in html
     assert "todaySync.enqueue('remove'" in html
     assert "todaySync.enqueue('move'" in html
+    assert "const authoritativeTodayReconciliation = liveMode && hasContextSnapshot &&" in html
+    assert "!lastContextSnapshot?.error &&" in html
+    assert "onPrune: retiredIds =>" in html
+    assert "retiredIds.map(id => todaySync.enqueue('remove', id)).every(Boolean)" in html
+    assert "if (queued) todaySync.flush();" in html
     assert "todaySync.flush();" in html
     assert "Another device filled Today · showing its saved plan." in html
 
 
+@pytest.mark.anyio
+async def test_dashboard_activates_today_lifecycle_convergence():
+    html = await dashboard()
+
+    assert "todaySync.startLifecycle({ window, document });" in html
+
+
 @pytest.mark.anyio
 async def test_retained_authenticated_context_keeps_local_planning_separate_from_fresh_delivery():
     html = await dashboard()
 
     assert "let planningOwnerLogin = '';" in html
-    assert html.count("getLogin: () => planningOwnerLogin") == 3
+    assert html.count("getLogin: () => planningOwnerLogin") == 4
     assert "const retainedPlanningLogin = !snapshot.context.error ?" in html
     assert "planningOwnerLogin = retainedPlanningLogin;" in html
     assert "button.disabled = !planningOwnerLogin;" in html