feat: enhance weekly report and realtime notifications

Weekly Report (fix-weekly-report):
- Remove 5-task limit, show all tasks per category
- Add blocked tasks with blocker_reason and blocked_since
- Add next week tasks (due in coming week)
- Add assignee_name, completed_at, days_overdue to task details
- Frontend collapsible sections for each task category
- 8 new tests for enhanced report content

Realtime Notifications (fix-realtime-notifications):
- SQLAlchemy event-based notification publishing
- Redis Pub/Sub for multi-process broadcast
- Fix soft rollback handler stacking issue
- Fix ping scheduling drift (send immediately when interval expires)
- Frontend NotificationContext with WebSocket reconnection

Spec Fixes:
- Add missing ## Purpose sections to 5 specs

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

frontend/src/contexts/NotificationContext.tsx

@@ -23,8 +23,8 @@ export function NotificationProvider({ children }: { children: ReactNode }) {
   const [loading, setLoading] = useState(false)
   const [error, setError] = useState<string | null>(null)
   const wsRef = useRef<WebSocket | null>(null)
-  const pingIntervalRef = useRef<NodeJS.Timeout | null>(null)
-  const reconnectTimeoutRef = useRef<NodeJS.Timeout | null>(null)
+  const pingIntervalRef = useRef<ReturnType<typeof setInterval> | null>(null)
+  const reconnectTimeoutRef = useRef<ReturnType<typeof setTimeout> | null>(null)
 
   const refreshUnreadCount = useCallback(async () => {
     try {
@@ -79,8 +79,15 @@ export function NotificationProvider({ children }: { children: ReactNode }) {
     const token = localStorage.getItem('token')
     if (!token) return
 
-    const wsProtocol = window.location.protocol === 'https:' ? 'wss:' : 'ws:'
-    const wsUrl = `${wsProtocol}//${window.location.host}/ws/notifications?token=${token}`
+    // Use env var if available, otherwise derive from current location
+    let wsUrl: string
+    const envWsUrl = import.meta.env.VITE_WS_URL
+    if (envWsUrl) {
+      wsUrl = `${envWsUrl}/ws/notifications?token=${token}`
+    } else {
+      const wsProtocol = window.location.protocol === 'https:' ? 'wss:' : 'ws:'
+      wsUrl = `${wsProtocol}//${window.location.host}/ws/notifications?token=${token}`
+    }
 
     try {
       const ws = new WebSocket(wsUrl)
@@ -101,6 +108,32 @@ export function NotificationProvider({ children }: { children: ReactNode }) {
           const message = JSON.parse(event.data)
 
           switch (message.type) {
+            case 'connected':
+              console.log('WebSocket authenticated:', message.data.message)
+              break
+
+            case 'unread_sync':
+              // Merge unread notifications without removing already-loaded notifications
+              setNotifications(prev => {
+                const unreadNotifications = message.data.notifications || []
+                const existingIds = new Set(prev.map(n => n.id))
+
+                // Add new unread notifications that don't exist in current list
+                const newNotifications = unreadNotifications.filter(
+                  (n: Notification) => !existingIds.has(n.id)
+                )
+
+                // Update existing unread notifications and prepend new ones
+                const updated = prev.map(existing => {
+                  const fromSync = unreadNotifications.find((n: Notification) => n.id === existing.id)
+                  return fromSync || existing
+                })
+
+                return [...newNotifications, ...updated]
+              })
+              setUnreadCount(message.data.unread_count || 0)
+              break
+
             case 'notification':
               // Add new notification to the top
               setNotifications(prev => [message.data, ...prev])
@@ -111,6 +144,13 @@ export function NotificationProvider({ children }: { children: ReactNode }) {
               setUnreadCount(message.data.unread_count)
               break
 
+            case 'ping':
+              // Server ping - respond with pong
+              if (ws.readyState === WebSocket.OPEN) {
+                ws.send(JSON.stringify({ type: 'pong' }))
+              }
+              break
+
             case 'pong':
               // Pong received, connection is alive
               break