feat: make Plan Today browser-back safe (#401)

frontend/dashboard.js

@@ -759,7 +759,11 @@
     }));
   }
 
-  function closePlanToday() {
+  function closePlanToday(navigate = true) {
+    if (navigate) {
+      taskOverlayHistory.close();
+      return;
+    }
     planToday.cancel();
     qs('#plan-today-sheet').hidden = true;
     document.body.classList.remove('task-overlay-open');
@@ -788,12 +792,16 @@
     },
   });
 
-  function openPlanToday(trigger) {
+  function openPlanToday(trigger, navigate = true) {
     if (!planningOwnerLogin) {
       qs('#my-work-action-status').textContent = 'Planning is unavailable until your operator identity is restored.';
       return;
     }
-    planTodayTrigger = trigger;
+    if (trigger) planTodayTrigger = trigger;
+    if (navigate) {
+      taskOverlayHistory.open('plan-today');
+      return;
+    }
     planToday.open(todayMyWork, activeMyWork);
     qs('#plan-today-error').textContent = '';
     qs('#plan-today-sheet').hidden = false;
@@ -2618,9 +2626,11 @@
         mobileSearchViewport.close();
         qs('#open-palette').focus();
       }
+      if (previous === 'plan-today' && kind !== 'plan-today') closePlanToday(false);
       if (kind === 'new' && previous !== 'new') openCreateIssueSheet(false);
       if (kind === 'find' && previous !== 'find') openFindWorkSheet(false);
       if (kind === 'search' && previous !== 'search-preview') openCommandPalette(false);
+      if (kind === 'plan-today' && previous !== 'plan-today') openPlanToday(planTodayTrigger, false);
     },
   });
   taskOverlayHistory.start();
@@ -3578,15 +3588,13 @@
   });
   qs('#save-today-plan').addEventListener('click', () => {
     const result = planToday.commit();
-    if (result === 'saved') closePlanToday();
+    if (result === 'saved') taskOverlayHistory.leave();
     else qs('#plan-today-error').textContent = 'Could not save the plan on this device. Free storage and retry.';
   });
   qs('#save-and-start-today').addEventListener('click', () => {
     const result = planToday.commit({ start:true });
-    if (result === 'saved') {
-      qs('#plan-today-sheet').hidden = true;
-      document.body.classList.remove('task-overlay-open');
-    } else qs('#plan-today-error').textContent = 'Could not save the plan on this device. Free storage and retry.';
+    if (result === 'saved') taskOverlayHistory.leave();
+    else qs('#plan-today-error').textContent = 'Could not save the plan on this device. Free storage and retry.';
   });
   qs('#start-work-session').addEventListener('click', () => {
     const sessionItems = selectedWorkFilter === 'today' ? todayMyWork : filterMyWork(lastMyWork, selectedWorkFilter);

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-v62';
+const CACHE = 'stackchain-dashboard-shell-v63';
 const OFFLINE_LEASE_URL = new URL(BASE + '__offline-session-lease', self.location.origin).href;
 const OUTAGE_STATUSES = new Set([500, 502, 503, 504]);
 const NAVIGATION_TIMEOUT_MS = self.__STACKCHAIN_NAVIGATION_TIMEOUT_MS || 4000;

frontend/task-overlay-history.js

@@ -5,7 +5,7 @@
 })(typeof globalThis !== 'undefined' ? globalThis : this, function () {
   'use strict';
 
-  const allowed = new Set(['new', 'find', 'search', 'search-preview']);
+  const allowed = new Set(['new', 'find', 'search', 'search-preview', 'plan-today']);
 
   return function createTaskOverlayHistory({ history, eventTarget, onChange }) {
     let active = allowed.has(history.state?.taskOverlay) ? history.state.taskOverlay : null;