feat(FN-3237): fix mobile viewport teardown when closing planning mode

Merges FN-3237 to stabilize the mobile viewport teardown flow when closing the planning modal, ensuring the viewport state resets correctly. Adds test coverage for the mobile planning close path and includes a changeset for the patch release.

Fusion-Task-Id: FN-3237

.changeset/fn-3237-mobile-planning-viewport-fix.md

@@ -0,0 +1,5 @@
+---
+"@runfusion/fusion": patch
+---
+
+Fix a mobile dashboard regression where closing Planning Mode after keyboard/visualViewport changes could leave board/list content shifted or clipped. Planning Mode now performs mobile viewport teardown (blur + top snap) on close so control returns cleanly to the dashboard.

packages/dashboard/app/components/PlanningModeModal.tsx

@@ -1178,6 +1178,22 @@ export function PlanningModeModal({ isOpen, onClose, onTaskCreated, onTasksCreat
   // Close the modal without abandoning the active server session. Sessions
   // remain in the list and can be resumed later. Only an explicit Delete
   // (from the sidebar) cancels and removes a session.
+  const resetMobileViewportAfterClose = useCallback(() => {
+    if (viewportMode !== "mobile") {
+      return;
+    }
+
+    const activeElement = document.activeElement;
+    if (activeElement instanceof HTMLElement) {
+      activeElement.blur();
+    }
+
+    window.scrollTo(0, 0);
+    requestAnimationFrame(() => {
+      window.scrollTo(0, 0);
+    });
+  }, [viewportMode]);
+
   const handleClose = useCallback(() => {
     // Save the in-progress draft so the next open restores it.
     if (initialPlan && view.type === "initial") {
@@ -1200,8 +1216,9 @@ export function PlanningModeModal({ isOpen, onClose, onTaskCreated, onTasksCreat
     streamConnectionRef.current = null;
     setIsReconnecting(false);
     setIsRetrying(false);
+    resetMobileViewportAfterClose();
     onClose();
-  }, [flushDraftAndSummarize, initialPlan, onClose, projectId, view.type]);
+  }, [flushDraftAndSummarize, initialPlan, onClose, projectId, resetMobileViewportAfterClose, view.type]);
 
   // Handle escape key to close
   useEffect(() => {
@@ -1475,12 +1492,12 @@ export function PlanningModeModal({ isOpen, onClose, onTaskCreated, onTasksCreat
       currentSessionIdRef.current = null;
       setLockSessionId(null);
       setSelectedSessionId(null);
-      onClose();
+      handleClose();
     } catch (err) {
       setError(getErrorMessage(err) || "Failed to create tasks");
       setView({ type: "breakdown", sessionId: view.sessionId, subtasks: view.subtasks, dirty: view.dirty });
     }
-  }, [broadcastCompleted, view, onTasksCreated, onClose, projectId]);
+  }, [broadcastCompleted, handleClose, view, onTasksCreated, projectId]);
 
   const handleBack = useCallback(() => {
     if (view.type === "question" && responseHistory.length > 0) {

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

@@ -349,6 +349,42 @@ describe("PlanningModeModal", () => {
       expect(screen.queryByText("Planning Mode")).toBeNull();
     });
 
+    it("mobile close path blurs focused input and resets viewport scroll", () => {
+      mockViewport("mobile");
+      const scrollToSpy = vi.spyOn(window, "scrollTo").mockImplementation(() => undefined);
+      const rafSpy = vi
+        .spyOn(window, "requestAnimationFrame")
+        .mockImplementation((callback: FrameRequestCallback) => {
+          callback(0);
+          return 1;
+        });
+
+      render(
+        <PlanningModeModal
+          isOpen={true}
+          onClose={mockOnClose}
+          onTaskCreated={mockOnTaskCreated}
+          onTasksCreated={vi.fn()}
+          tasks={mockTasks}
+        />
+      );
+
+      const textarea = screen.getByPlaceholderText(/e.g., Build a user authentication/) as HTMLTextAreaElement;
+      act(() => {
+        textarea.focus();
+      });
+      const blurSpy = vi.spyOn(textarea, "blur");
+
+      act(() => {
+        fireEvent.click(screen.getByRole("button", { name: "Close" }));
+      });
+
+      expect(blurSpy).toHaveBeenCalledTimes(1);
+      expect(scrollToSpy).toHaveBeenCalledWith(0, 0);
+      expect(rafSpy).toHaveBeenCalled();
+      expect(mockOnClose).toHaveBeenCalledTimes(1);
+    });
+
     it("hides send to background button in initial state", () => {
       render(
         <PlanningModeModal