fix: preserve task lane answers across page reload and browser close

Two issues fixed:

1. TaskLane useEffect on [questions, actions] was resetting all tasks
   to pending with empty values, wiping restored user answers. Now
   checks sessionStorage for saved state before resetting.

2. selectChat was setting activeQuestions/activeActions before writing
   responses to sessionStorage, causing a race where TaskLane mounted
   with new props but empty sessionStorage. Now writes responses to
   sessionStorage first so TaskLane can restore them on prop change.

The backend saveTaskLane debounce (2s) persists responses to the DB,
and selectChat restores them via pending_task_lane.responses. This
chain now survives browser close.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

frontend/src/components/assistant/TaskLane.tsx

@@ -147,8 +147,16 @@ export function TaskLane({ questions, actions, sessionId, onSubmit, onClose, loa
     return () => { if (saveTimerRef.current) clearTimeout(saveTimerRef.current) }
   }, [sessionId, tasks]) // eslint-disable-line react-hooks/exhaustive-deps
 
-  // Reset when new tasks come in from AI response
+  // Reset when new tasks come in from AI response — but preserve saved state
   useEffect(() => {
+    if (sessionId) {
+      const saved = loadTaskState(sessionId)
+      if (saved && saved.length > 0) {
+        // eslint-disable-next-line react-hooks/set-state-in-effect -- intentional: syncs derived state from prop changes
+        setTasks(saved)
+        return
+      }
+    }
     // eslint-disable-next-line react-hooks/set-state-in-effect -- intentional: syncs derived state from prop changes
     setTasks([
       ...questions.map((q): QuestionResponse => ({
@@ -158,7 +166,7 @@ export function TaskLane({ questions, actions, sessionId, onSubmit, onClose, loa
         type: 'action', label: a.label, command: a.command, description: a.description, state: 'pending', value: '',
       })),
     ])
-  }, [questions, actions])
+  }, [questions, actions]) // eslint-disable-line react-hooks/exhaustive-deps
 
   const updateTask = (idx: number, updates: Partial<TaskResponse>) => {
     setTasks(prev => prev.map((t, i) => i === idx ? { ...t, ...updates } as TaskResponse : t))

frontend/src/pages/AssistantChatPage.tsx

@@ -232,16 +232,17 @@ export default function AssistantChatPage() {
         const q = detail.pending_task_lane.questions || []
         const a = detail.pending_task_lane.actions || []
         if (q.length > 0 || a.length > 0) {
-          setActiveQuestions(q)
-          setActiveActions(a)
-          setShowTaskLane(true)
-          // Pre-load user's saved responses into sessionStorage so TaskLane restores them
+          // Pre-load user's saved responses into sessionStorage BEFORE setting props
+          // so TaskLane can restore them on mount/prop-change
           const responses = (detail.pending_task_lane as Record<string, unknown>).responses as unknown[] | undefined
           if (responses && responses.length > 0) {
             try {
               sessionStorage.setItem(`rf-tasklane-state:${chatId}`, JSON.stringify(responses))
             } catch { /* ignore */ }
           }
+          setActiveQuestions(q)
+          setActiveActions(a)
+          setShowTaskLane(true)
         }
       }
     } catch {