feat(FN-3935): align engineer role routing with explicit assignment and del

Centralized routing policy helpers in core and aligned both direct assignment and delegation to route engineer-role agents consistently, ensuring assigned tasks respect explicit engineer routing the same way delegated tasks do. Added comprehensive test coverage across core, CLI, dashboard, and engin

Fusion-Task-Id: FN-3935

Fusion-Task-Lineage: 069f4d54-f7a8-4bd3-a2c3-4de830de042f

packages/cli/src/commands/__tests__/db.test.ts

@@ -0,0 +1,114 @@
+import { describe, it, expect, vi, beforeEach, afterEach } from "vitest";
+
+// Hoist mocks so they are evaluated before module imports
+const { mockGetDatabase, mockVacuum, mockResolveProject } = vi.hoisted(() => ({
+  mockGetDatabase: vi.fn(),
+  mockVacuum: vi.fn(),
+  mockResolveProject: vi.fn(),
+}));
+
+vi.mock("@fusion/core", () => ({
+  TaskStore: vi.fn().mockImplementation(() => ({
+    init: vi.fn(),
+    getDatabase: mockGetDatabase,
+  })),
+}));
+
+vi.mock("../../project-context.js", () => ({
+  resolveProject: mockResolveProject,
+}));
+
+import { runDbVacuum } from "../db.ts";
+
+describe("runDbVacuum", () => {
+  let logSpy: ReturnType<typeof vi.spyOn>;
+  let errorSpy: ReturnType<typeof vi.spyOn>;
+  let exitSpy: ReturnType<typeof vi.spyOn>;
+
+  beforeEach(() => {
+    vi.clearAllMocks();
+    logSpy = vi.spyOn(console, "log").mockImplementation(() => {});
+    errorSpy = vi.spyOn(console, "error").mockImplementation(() => {});
+    exitSpy = vi.spyOn(process, "exit").mockImplementation((code?: string | number | null) => {
+      throw new Error(`process.exit:${code ?? 0}`);
+    });
+  });
+
+  afterEach(() => {
+    logSpy.mockRestore();
+    errorSpy.mockRestore();
+    exitSpy.mockRestore();
+  });
+
+  it("resolves project store and calls vacuum", async () => {
+    mockResolveProject.mockResolvedValue({
+      projectId: "proj-1",
+      projectName: "demo-project",
+      projectPath: "/projects/demo",
+      isRegistered: true,
+      store: { getDatabase: mockGetDatabase },
+    });
+    mockGetDatabase.mockReturnValue({
+      vacuum: mockVacuum.mockReturnValue({
+        beforeSize: 10_485_760,
+        afterSize: 7_340_416,
+        durationMs: 123,
+      }),
+      getPath: () => "/projects/demo/.fusion/fusion.db",
+    });
+
+    await expect(runDbVacuum("demo-project")).rejects.toThrow("process.exit:0");
+    expect(mockResolveProject).toHaveBeenCalledWith("demo-project");
+    expect(mockVacuum).toHaveBeenCalled();
+    expect(logSpy).toHaveBeenCalledWith(expect.stringContaining("VACUUM"));
+  });
+
+  it("exits 1 on vacuum error", async () => {
+    mockResolveProject.mockResolvedValue({
+      projectId: "proj-1",
+      projectName: "demo-project",
+      projectPath: "/projects/demo",
+      isRegistered: true,
+      store: { getDatabase: mockGetDatabase },
+    });
+    mockGetDatabase.mockReturnValue({
+      vacuum: mockVacuum.mockRejectedValue(new Error("database locked")),
+      getPath: () => "/projects/demo/.fusion/fusion.db",
+    });
+
+    await expect(runDbVacuum("demo-project")).rejects.toThrow("process.exit:1");
+    expect(errorSpy).toHaveBeenCalledWith(expect.stringContaining("database locked"));
+  });
+
+  it("falls back to cwd TaskStore when resolveProject fails", async () => {
+    const cwdSpy = vi.spyOn(process, "cwd").mockReturnValue("/fallback/project");
+    mockResolveProject.mockRejectedValue(new Error("no project"));
+
+    const mockStore = { init: vi.fn(), getDatabase: mockGetDatabase };
+    mockGetDatabase.mockReturnValue({
+      vacuum: mockVacuum.mockReturnValue({ beforeSize: 0, afterSize: 0, durationMs: 0 }),
+      getPath: () => "/fallback/project/.fusion/fusion.db",
+    });
+
+    await expect(runDbVacuum("missing")).rejects.toThrow("process.exit:0");
+    expect(mockResolveProject).toHaveBeenCalledWith("missing");
+    cwdSpy.mockRestore();
+  });
+
+  it("skips vacuum on in-memory database (returns zero sizes)", async () => {
+    mockResolveProject.mockResolvedValue({
+      projectId: "proj-1",
+      projectName: "mem-project",
+      projectPath: "/mem",
+      isRegistered: true,
+      store: { getDatabase: mockGetDatabase },
+    });
+    mockGetDatabase.mockReturnValue({
+      vacuum: mockVacuum.mockReturnValue({ beforeSize: 0, afterSize: 0, durationMs: 0 }),
+      getPath: () => ":memory:",
+    });
+
+    await expect(runDbVacuum("mem-project")).rejects.toThrow("process.exit:0");
+    expect(logSpy).toHaveBeenCalledWith(expect.stringContaining("in-memory"));
+  });
+});