refactor(FN-1289): extract AppInner logic into hooks and modal component

- Extract view state, project actions, and task handler concerns from AppInner into dedicated hooks
- Add AppModals component to centralize modal rendering and related props wiring
- Inline thin aliases and complete AppInner cleanup after moving responsibilities out
- Add unit tests for useViewState, useProjectActions, and useTaskHandlers hooks

packages/dashboard/app/hooks/__tests__/useTaskHandlers.test.ts

@@ -0,0 +1,106 @@
+import { act, renderHook } from "@testing-library/react";
+import { beforeEach, describe, expect, it, vi } from "vitest";
+import { useTaskHandlers } from "../useTaskHandlers";
+import type { Task, TaskCreateInput } from "@fusion/core";
+
+const CREATED_TASK: Task = {
+  id: "FN-123",
+  title: "Test",
+  description: "Created task",
+  status: "pending",
+  column: "triage",
+  steps: [],
+  dependencies: [],
+  log: [],
+  attachments: [],
+  createdAt: "",
+  updatedAt: "",
+  size: "M",
+  reviewLevel: 0,
+};
+
+function createOptions(overrides: Partial<Parameters<typeof useTaskHandlers>[0]> = {}): Parameters<typeof useTaskHandlers>[0] {
+  return {
+    createTask: vi.fn().mockResolvedValue(CREATED_TASK),
+    onPlanningTaskCreated: vi.fn(),
+    onPlanningTasksCreated: vi.fn(),
+    onSubtaskTasksCreated: vi.fn(),
+    addToast: vi.fn(),
+    ...overrides,
+  };
+}
+
+describe("useTaskHandlers", () => {
+  beforeEach(() => {
+    vi.clearAllMocks();
+  });
+
+  it("handleBoardQuickCreate calls createTask with triage column", async () => {
+    const options = createOptions();
+    const { result } = renderHook(() => useTaskHandlers(options));
+    const input: TaskCreateInput = { description: "Do work" };
+
+    await act(async () => {
+      await result.current.handleBoardQuickCreate(input);
+    });
+
+    expect(options.createTask).toHaveBeenCalledWith({ description: "Do work", column: "triage" });
+  });
+
+  it("handleModalCreate calls createTask with triage column and returns task", async () => {
+    const options = createOptions();
+    const { result } = renderHook(() => useTaskHandlers(options));
+
+    let created: Task | null = null;
+    await act(async () => {
+      created = await result.current.handleModalCreate({ description: "From modal" });
+    });
+
+    expect(options.createTask).toHaveBeenCalledWith({ description: "From modal", column: "triage" });
+    expect(created).toEqual(CREATED_TASK);
+  });
+
+  it("handlePlanningTaskCreated delegates with addToast", () => {
+    const options = createOptions();
+    const { result } = renderHook(() => useTaskHandlers(options));
+
+    act(() => {
+      result.current.handlePlanningTaskCreated(CREATED_TASK);
+    });
+
+    expect(options.onPlanningTaskCreated).toHaveBeenCalledWith(CREATED_TASK, options.addToast);
+  });
+
+  it("handlePlanningTasksCreated delegates with addToast", () => {
+    const options = createOptions();
+    const { result } = renderHook(() => useTaskHandlers(options));
+
+    act(() => {
+      result.current.handlePlanningTasksCreated([CREATED_TASK]);
+    });
+
+    expect(options.onPlanningTasksCreated).toHaveBeenCalledWith([CREATED_TASK], options.addToast);
+  });
+
+  it("handleSubtaskTasksCreated delegates with addToast", () => {
+    const options = createOptions();
+    const { result } = renderHook(() => useTaskHandlers(options));
+
+    act(() => {
+      result.current.handleSubtaskTasksCreated([CREATED_TASK]);
+    });
+
+    expect(options.onSubtaskTasksCreated).toHaveBeenCalledWith([CREATED_TASK], options.addToast);
+  });
+
+  it("handleGitHubImport shows success toast with task ID", () => {
+    const options = createOptions();
+    const { result } = renderHook(() => useTaskHandlers(options));
+
+    act(() => {
+      result.current.handleGitHubImport(CREATED_TASK);
+    });
+
+    expect(options.addToast).toHaveBeenCalledWith("Imported FN-123 from GitHub", "success");
+  });
+});