fix: isolate Today summary drafts by account

frontend/today-summary.js

@@ -1,16 +1,27 @@
 function createTodaySummary({ storage = null, getLogin = () => '', share = null, copy = null } = {}) {
   let draft = null;
+  let draftKey = '';
 
   const storageKey = () => {
     const login = String(getLogin() || '').trim().toLowerCase();
     return login ? 'stackchain.today-summary-draft.v1.' + login : '';
   };
+  const syncAccount = () => {
+    const key = storageKey();
+    if (key !== draftKey) {
+      draft = null;
+      draftKey = key;
+    }
+  };
   const copyRows = rows => rows.map(row => ({ ...row }));
-  const snapshot = () => draft ? {
-    ...draft,
-    worked:copyRows(draft.worked),
-    tomorrow:copyRows(draft.tomorrow),
-  } : null;
+  const snapshot = () => {
+    syncAccount();
+    return draft ? {
+      ...draft,
+      worked:copyRows(draft.worked),
+      tomorrow:copyRows(draft.tomorrow),
+    } : null;
+  };
   const persist = () => {
     const key = storageKey();
     if (storage && key && draft) storage.setItem(key, JSON.stringify(draft));
@@ -58,6 +69,7 @@ function createTodaySummary({ storage = null, getLogin = () => '', share = null,
 
   return {
     begin(worked, tomorrow) {
+      draftKey = storageKey();
       draft = {
         worked:(worked || []).filter(row => row?.identity).slice(0, 20).map(row => cleanRow(row, true)),
         tomorrow:(tomorrow || []).filter(row => row?.identity).slice(0, 20).map(row => cleanRow(row, false)),
@@ -69,10 +81,12 @@ function createTodaySummary({ storage = null, getLogin = () => '', share = null,
     },
     snapshot,
     restore() {
+      draftKey = storageKey();
       draft = load();
       return Boolean(draft);
     },
     choose(section, identity, include) {
+      syncAccount();
       const row = draft?.[section]?.find(candidate => candidate.identity === identity);
       if (!row || typeof include !== 'boolean') return false;
       row.include = include;
@@ -80,12 +94,14 @@ function createTodaySummary({ storage = null, getLogin = () => '', share = null,
       return true;
     },
     includeActuals(include) {
+      syncAccount();
       if (!draft || typeof include !== 'boolean') return false;
       draft.include_actuals = include;
       persist();
       return true;
     },
     setNote(note) {
+      syncAccount();
       if (!draft) return false;
       draft.note = String(note || '').trim().slice(0, 1000);
       persist();
@@ -93,6 +109,7 @@ function createTodaySummary({ storage = null, getLogin = () => '', share = null,
     },
     discard,
     text() {
+      syncAccount();
       if (!draft) return '';
       const sections = [];
       const worked = selectedLines(draft.worked, draft.include_actuals);