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>

backend/alembic/versions/fc01_add_pending_task_lane.py

@@ -0,0 +1,30 @@
+"""add pending_task_lane to ai_sessions
+
+Revision ID: fc01a1b2c3d4
+Revises: fb1481317ff6
+Create Date: 2026-03-27
+"""
+from alembic import op
+import sqlalchemy as sa
+from sqlalchemy.dialects.postgresql import JSONB
+
+revision = "fc01a1b2c3d4"
+down_revision = "fb1481317ff6"
+branch_labels = None
+depends_on = None
+
+
+def upgrade() -> None:
+    op.add_column(
+        "ai_sessions",
+        sa.Column(
+            "pending_task_lane",
+            JSONB,
+            nullable=True,
+            comment="Current task lane state: {questions: [...], actions: [...]}",
+        ),
+    )
+
+
+def downgrade() -> None:
+    op.drop_column("ai_sessions", "pending_task_lane")

backend/app/models/ai_session.py

@@ -209,6 +209,10 @@ class AISession(Base):
         JSONB, nullable=False, default=list,
         comment="Full LLM message history for context continuity",
     )
+    pending_task_lane: Mapped[Optional[dict[str, Any]]] = mapped_column(
+        JSONB, nullable=True,
+        comment="Current task lane state: {questions: [...], actions: [...]}",
+    )
 
     # ── Branching ──
     is_branching: Mapped[bool] = mapped_column(

backend/app/schemas/ai_session.py

@@ -228,6 +228,7 @@ class AISessionDetail(AISessionSummary):
     ticket_data: dict[str, Any] | None = None
     steps: list[AISessionStepResponse] = []
     conversation_messages: list[dict[str, Any]] = []  # Chat sessions store messages here
+    pending_task_lane: dict[str, Any] | None = None
     is_branching: bool = False
     active_branch_id: str | None = None
 

backend/app/services/unified_chat_service.py

@@ -286,6 +286,15 @@ async def send_chat_message(
                 except Exception:
                     logger.exception("Failed to create fork within branch for session %s", session.id)
 
+            # Persist task lane state on session
+            if branch_questions_data or branch_actions_data:
+                session.pending_task_lane = {
+                    "questions": branch_questions_data or [],
+                    "actions": branch_actions_data or [],
+                }
+            else:
+                session.pending_task_lane = None
+
             suggested_flows = extract_suggested_flows(
                 await rag_search(query=message, account_id=account_id, db=db, limit=8)
             )
@@ -393,6 +402,15 @@ async def send_chat_message(
             logger.exception("Failed to create fork for session %s", session_id)
             # Fork failed but chat message still sent — don't break the response
 
+    # Persist task lane state on session
+    if questions_data or actions_data:
+        session.pending_task_lane = {
+            "questions": questions_data or [],
+            "actions": actions_data or [],
+        }
+    else:
+        session.pending_task_lane = None
+
     suggested_flows = extract_suggested_flows(rag_results)
 
     return display_content, suggested_flows, session, fork_metadata, actions_data, questions_data

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
 }