feat(FN-3447): add planning session rewind capability with modal back actio

This merge delivers four major features: a planning session rewind system (FN-3447, steps 1–4) with a new backend route for rolling back sessions, modal back-action wiring, and updated typing; workspace verification gates (FN-3385) for agent prompt editing; an agents view org chart spacing rework (F

Fusion-Task-Id: FN-3447

packages/dashboard/app/components/PlanningModeModal.tsx

@@ -6,6 +6,7 @@ import {
   startPlanningStreaming,
   createPlanningDraft,
   respondToPlanning,
+  rewindPlanningSession,
   retryPlanningSession,
   createTaskFromPlanning,
   connectPlanningStream,
@@ -1499,16 +1500,45 @@ export function PlanningModeModal({ isOpen, onClose, onTaskCreated, onTasksCreat
     }
   }, [broadcastCompleted, handleClose, view, onTasksCreated, projectId]);
 
-  const handleBack = useCallback(() => {
-    if (view.type === "question" && responseHistory.length > 0) {
-      // Remove last response and go back
-      const previousResponses = responseHistory.slice(0, -1);
-      setResponseHistory(previousResponses);
-      // Note: We don't actually have a way to go back in the backend,
-      // so we just reset to the question from the initial session
+  const handleBack = useCallback(async () => {
+    if (view.type !== "question" || responseHistory.length === 0) {
+      return;
+    }
+
+    const sessionId = view.session.sessionId;
+    setError(null);
+    setView({ type: "loading" });
+
+    try {
+      const rewound = await rewindPlanningSession(sessionId, projectId, sessionTabId);
+      setResponseHistory(rewound.history.map((entry) => {
+        if (entry.response && typeof entry.response === "object" && !Array.isArray(entry.response)) {
+          return entry.response as QuestionResponse;
+        }
+        return { [entry.question.id]: entry.response };
+      }));
+      setConversationHistory(rewound.history.map((entry) => ({
+        question: entry.question,
+        response:
+          entry.response && typeof entry.response === "object" && !Array.isArray(entry.response)
+            ? (entry.response as Record<string, unknown>)
+            : { [entry.question.id]: entry.response },
+        thinkingOutput: entry.thinkingOutput,
+      })));
+      setStreamingOutput("");
+      setView({
+        type: "question",
+        session: {
+          ...view.session,
+          currentQuestion: rewound.currentQuestion,
+          summary: null,
+        },
+      });
+    } catch (err) {
+      setError(getErrorMessage(err) || "Failed to go back to the previous question");
       setView({ type: "question", session: view.session });
     }
-  }, [view, responseHistory]);
+  }, [projectId, responseHistory.length, sessionTabId, view]);
 
   const getProgress = () => {
     if (view.type === "question") {

packages/dashboard/app/components/__tests__/PlanningModeModal.questions.test.tsx

@@ -12,6 +12,7 @@ import {
   mockCreatePlanningDraft,
   mockConnectPlanningStream,
   mockRespondToPlanning,
+  mockRewindPlanningSession,
   mockRetryPlanningSession,
   mockCancelPlanning,
   mockStopPlanningGeneration,
@@ -55,8 +56,8 @@ vi.mock("../../api", () => ({
   createPlanningDraft: (...args: any[]) => mockCreatePlanningDraft(...args),
   connectPlanningStream: (...args: any[]) => mockConnectPlanningStream(...args),
   respondToPlanning: (...args: any[]) => mockRespondToPlanning(...args),
-  retryPlanningSession: (...args: any[]) => mockRetryPlanningSession(...args),
-  cancelPlanning: (...args: any[]) => mockCancelPlanning(...args),
+  rewindPlanningSession: (...args: any[]) => mockRewindPlanningSession(...args),
+  retryPlanningSession: (...args: any[]) => mockRetryPlanningSession(...args),  cancelPlanning: (...args: any[]) => mockCancelPlanning(...args),
   stopPlanningGeneration: (...args: any[]) => mockStopPlanningGeneration(...args),
   updatePlanningSessionDraft: (...args: any[]) => mockUpdatePlanningSessionDraft(...args),
   createTaskFromPlanning: (...args: any[]) => mockCreateTaskFromPlanning(...args),
@@ -121,6 +122,7 @@ describe("PlanningModeModal", () => {
     // the sidebar render rule (preview while title === placeholder) behaves
     // realistically in tests.
     mockCreatePlanningDraft.mockResolvedValue({ sessionId: "draft-123", title: "New planning session" });
+    mockRewindPlanningSession.mockResolvedValue({ currentQuestion: mockQuestion, history: [] });
     mockRetryPlanningSession.mockResolvedValue({ success: true, sessionId: "session-123" });
     mockStartPlanningBreakdown.mockResolvedValue({ sessionId: "session-123", subtasks: [] });
     mockFetchAiSession.mockResolvedValue(null);
@@ -583,6 +585,66 @@ describe("PlanningModeModal", () => {
       expect(screen.queryByPlaceholderText("Add any extra context or direction...")).not.toBeInTheDocument();
     });
 
+    it("rewinds to the previous question when Back is clicked", async () => {
+      let streamHandlers: any;
+      const secondQuestion: PlanningQuestion = {
+        id: "q-requirements",
+        type: "text",
+        question: "What are the key requirements?",
+      };
+
+      mockConnectPlanningStream.mockImplementationOnce((_sessionId: string, _projectId: string | undefined, handlers: any) => {
+        streamHandlers = handlers;
+        setTimeout(() => {
+          handlers.onQuestion?.(mockQuestion);
+        }, 10);
+        return {
+          close: vi.fn(),
+          isConnected: vi.fn().mockReturnValue(true),
+        };
+      });
+
+      mockRespondToPlanning.mockImplementationOnce(async () => {
+        setTimeout(() => {
+          streamHandlers?.onQuestion?.(secondQuestion);
+        }, 10);
+        return { type: "question", data: secondQuestion };
+      });
+
+      mockRewindPlanningSession.mockResolvedValueOnce({
+        currentQuestion: mockQuestion,
+        history: [],
+      });
+
+      render(
+        <PlanningModeModal
+          isOpen={true}
+          onClose={mockOnClose}
+          onTaskCreated={mockOnTaskCreated}
+          onTasksCreated={vi.fn()}
+          tasks={mockTasks}
+        />,
+      );
+
+      fireEvent.change(screen.getByPlaceholderText(/e.g., Build a user authentication/), {
+        target: { value: "Build auth system" },
+      });
+      fireEvent.click(screen.getByText("Start Planning"));
+
+      await screen.findByText("What is the scope?");
+      fireEvent.click(screen.getByText("Medium"));
+      fireEvent.click(screen.getByRole("button", { name: "Continue" }));
+
+      await screen.findByText("What are the key requirements?");
+      fireEvent.click(screen.getByRole("button", { name: "Back" }));
+
+      await waitFor(() => {
+        expect(mockRewindPlanningSession).toHaveBeenCalledWith("session-123", undefined, expect.any(String));
+      });
+      expect(await screen.findByText("What is the scope?")).toBeInTheDocument();
+      expect(screen.queryByText("What are the key requirements?")).toBeNull();
+    });
+
     it("includes _comment in response when comment is filled", async () => {
       render(
         <PlanningModeModal

packages/dashboard/app/components/__tests__/PlanningModeModal.test-helpers.ts

@@ -6,6 +6,7 @@ export const mockStartPlanningStreaming = vi.fn();
 export const mockCreatePlanningDraft = vi.fn();
 export const mockConnectPlanningStream = vi.fn();
 export const mockRespondToPlanning = vi.fn();
+export const mockRewindPlanningSession = vi.fn();
 export const mockRetryPlanningSession = vi.fn();
 export const mockCancelPlanning = vi.fn();
 export const mockStopPlanningGeneration = vi.fn();