feat: persist task lane across submits and session reloads

Task lane questions/actions are now saved to a pending_task_lane JSONB
column on ai_sessions, restoring them on session switch or page reload.
Partial submit no longer force-clears the lane — the AI response
controls what stays. Also removes redundant "New Session" button from
the sidebar (dashboard already provides this).

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

frontend/src/components/layout/Sidebar.tsx

@@ -5,7 +5,7 @@ import {
   LayoutGrid, Clock, AlertTriangle, GitBranch, Code2, Wand2,
   ListChecks, Download, BarChart3,
   Settings, Pin, PinOff,
-  Plus, History, FileText,
+  History, FileText,
 } from 'lucide-react'
 import { cn } from '@/lib/utils'
 import { useUserPreferencesStore } from '@/store/userPreferencesStore'
@@ -363,17 +363,6 @@ export function Sidebar() {
         style={{ background: 'var(--color-bg-sidebar)', borderRight: '1px solid var(--color-border-default)' }}
         onWheel={handleWheel}
       >
-        {/* New Session button */}
-        <div className="px-3 pt-3 pb-1">
-          <Link
-            to="/"
-            className="flex items-center justify-center gap-2 w-full rounded-lg bg-amber-400/15 py-2.5 text-sm font-semibold text-amber-400 hover:bg-amber-400/25 transition-colors"
-          >
-            <Plus size={16} strokeWidth={2} />
-            New Session
-          </Link>
-        </div>
-
         {/* Pinned sidebar content */}
         <div className="px-3 py-2 space-y-0.5">
           {sections.map((section, si) => (
@@ -420,18 +409,6 @@ export function Sidebar() {
         style={{ background: 'var(--color-bg-sidebar)', borderRight: '1px solid var(--color-border-default)', width: '72px' }}
         onWheel={handleWheel}
       >
-        {/* New Session button */}
-        <div className="w-full px-2 pt-4 pb-2">
-          <Link
-            to="/"
-            className="flex flex-col items-center justify-center w-full rounded-lg bg-amber-400/15 py-2.5 text-amber-400 hover:bg-amber-400/25 transition-colors"
-            title="New Session"
-          >
-            <Plus size={20} strokeWidth={2} />
-            <span className="mt-1 text-[0.5625rem] font-sans font-semibold">New</span>
-          </Link>
-        </div>
-
         {/* Nav items */}
         <div className="flex flex-col items-center w-full px-1 space-y-1.5">
           {railGroups.map((item, i) => renderRailItem(item, `rail-${i}`))}

frontend/src/hooks/useFlowPilotSession.ts

@@ -92,6 +92,7 @@ export function useFlowPilotSession(): UseFlowPilotSession {
         ticket_data: null,
         steps: [firstStep],
         conversation_messages: [],
+        pending_task_lane: null,
         is_branching: false,
         active_branch_id: null,
       })

frontend/src/pages/AssistantChatPage.tsx

@@ -160,7 +160,7 @@ export default function AssistantChatPage() {
 
   const selectChat = useCallback(async (chatId: string) => {
     setActiveChatId(chatId)
-    // Clear TaskLane when switching chats
+    // Clear TaskLane when switching chats — will restore from backend if available
     setShowTaskLane(false)
     setActiveQuestions([])
     setActiveActions([])
@@ -172,6 +172,16 @@ export default function AssistantChatPage() {
           content: m.content,
         }))
       )
+      // Restore task lane from persisted state
+      if (detail.pending_task_lane) {
+        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)
+        }
+      }
     } catch {
       setMessages([])
     }
@@ -288,11 +298,6 @@ export default function AssistantChatPage() {
     }
     const userMessage = parts.join('\n\n')
 
-    // Close the task lane
-    setShowTaskLane(false)
-    setActiveQuestions([])
-    setActiveActions([])
-
     setMessages(prev => [...prev, { role: 'user', content: userMessage }])
     setLoading(true)
 

frontend/src/types/ai-session.ts

@@ -195,6 +195,7 @@ export interface AISessionDetail extends AISessionSummary {
   ticket_data: Record<string, unknown> | null
   steps: AISessionStepResponse[]
   conversation_messages: Array<{ role: string; content: string }>
+  pending_task_lane: { questions: QuestionItem[]; actions: ActionItem[] } | null
   is_branching: boolean
   active_branch_id: string | null
 }