refactor(core): overhaul state transition architecture, persistent job queue, and API layer

- Implement atomic state transitions: add EntryService.PatchEntry() with EntryDiff computation and EventEntryTransition event emission.
- Add persistent SQLite task queue (JobEngine): add jobs table with crash recovery, exponential backoff retries, concurrency control, and idempotency key deduplication.
- Decompose monolithic HTTP handlers: split handlers.go into domain handlers (auth, feeds, entries, jobs, settings, rules, sse).
- Implement real-time Server-Sent Events (/api/events/stream) for multi-tab/device state synchronization.
- Fix SQLite concurrency: apply busy_timeout(10000) and journal_mode(WAL) via DSN query parameters to resolve SQLITE_BUSY (5).
- Fix AI settings & prompt loading: unmarshal JSON from ai_settings, apply configured prompt templates, and enforce strict enabled/API key validations.
- Fix undo share state: remove omitempty from ShareUUID to serialize null for state resets.
- Fix middle list counter: compute true unread/total stats from DB and clean switcher button labels.
- Adapt mobile UI for iOS: add viewport-fit=cover in index.html and calibrate safe-area insets for the bottom navigation and article reader toolbar.
- Add architectural documentation and worklog in docs/009_worklog.md.

web/src/App.tsx

@@ -306,9 +306,57 @@ export const App: React.FC = () => {
     }
   };
 
+  // Connect Real-Time SSE Stream for live state sync across tabs and async background jobs
+  useEffect(() => {
+    if (!currentUser) return;
+
+    const disconnect = api.connectEventStream((eventType, data) => {
+      if (eventType === 'job_completed' || eventType === 'post_updated' || eventType === 'variant_updated') {
+        const updatedEntry = data?.entry || data;
+        if (updatedEntry && updatedEntry.id) {
+          setEntries((prev) =>
+            prev.map((e) =>
+              e.id === updatedEntry.id
+                ? {
+                    ...e,
+                    ...updatedEntry,
+                    variants: { ...(e.variants || {}), ...(updatedEntry.variants || {}) },
+                  }
+                : e
+            )
+          );
+        }
+      } else if (eventType === 'post_created') {
+        loadSidebarData();
+      } else if (eventType === 'preferences_updated') {
+        if (data && typeof data === 'object') {
+          if (data.auto_read !== undefined) {
+            localStorage.setItem('rsspipe_auto_read_scroll', data.auto_read ? 'true' : 'false');
+          }
+          if (data.view_preference) {
+            setViewPreference(data.view_preference);
+            localStorage.setItem('rsspipe_view_preference', data.view_preference);
+          }
+        }
+      }
+    });
+
+    return () => disconnect();
+  }, [currentUser, loadSidebarData]);
+
   // Update Single Entry Action
   const handleUpdateEntry = (updated: FeedEntry) => {
-    setEntries((prev) => prev.map((e) => (e.id === updated.id ? updated : e)));
+    setEntries((prev) =>
+      prev.map((e) =>
+        e.id === updated.id
+          ? {
+              ...e,
+              ...updated,
+              variants: { ...(e.variants || {}), ...(updated.variants || {}) },
+            }
+          : e
+      )
+    );
     loadSidebarData();
   };
 
@@ -500,6 +548,7 @@ export const App: React.FC = () => {
           onMarkAllRead={handleMarkAllRead}
           onUpdateEntry={handleUpdateEntry}
           stats={stats}
+          totalEntries={totalEntries}
           onOpenSettings={() => setViewMode('settings')}
           onOpenAddFeed={() => setShowAddFeedModal(true)}
           onPlayAudio={handlePlayAudio}