perf: speed up slow git tests from ~18s to ~5.5s

- branch-manager: beforeEach→beforeAll (all 12 tests are read-only)
- worktree manager: clone template repo per test instead of full init
- signal-manager: reduce setTimeout delay from 100ms to 30ms

apps/server/agent/lifecycle/signal-manager.test.ts

@@ -133,7 +133,7 @@ describe('FileSystemSignalManager', () => {
       // Write signal after a delay
       setTimeout(async () => {
         await writeFile(signalPath, JSON.stringify(expectedSignal));
-      }, 100);
+      }, 30);
 
       const signal = await signalManager.waitForSignal(agentWorkdir, 1000);
       expect(signal).toEqual(expectedSignal);

apps/server/git/manager.test.ts

@@ -5,7 +5,7 @@
  * Uses temporary git repositories for each test.
  */
 
-import { describe, it, expect, beforeEach, afterEach } from 'vitest';
+import { describe, it, expect, beforeEach, afterEach, beforeAll, afterAll } from 'vitest';
 import { mkdtemp, rm, writeFile, mkdir } from 'node:fs/promises';
 import { tmpdir } from 'node:os';
 import path from 'node:path';
@@ -48,16 +48,34 @@ async function createTestRepo(): Promise<{
 }
 
 describe('SimpleGitWorktreeManager', () => {
+  let templatePath: string;
+  let templateCleanup: () => Promise<void>;
   let repoPath: string;
   let cleanup: () => Promise<void>;
   let manager: SimpleGitWorktreeManager;
   let eventBus: EventBus;
   let emittedEvents: Array<{ type: string; payload: unknown }>;
 
-  beforeEach(async () => {
+  beforeAll(async () => {
     const testRepo = await createTestRepo();
-    repoPath = testRepo.repoPath;
-    cleanup = testRepo.cleanup;
+    templatePath = testRepo.repoPath;
+    templateCleanup = testRepo.cleanup;
+  });
+
+  afterAll(async () => {
+    await templateCleanup();
+  });
+
+  beforeEach(async () => {
+    // Clone the template repo locally (hard-links, ~10ms vs ~50ms full init)
+    repoPath = await mkdtemp(path.join(tmpdir(), 'cw-test-repo-'));
+    await rm(repoPath, { recursive: true, force: true });
+    const git = simpleGit();
+    await git.clone(templatePath, repoPath, ['--local']);
+
+    cleanup = async () => {
+      await rm(repoPath, { recursive: true, force: true });
+    };
 
     // Create event bus and track emitted events
     eventBus = new EventEmitterBus();

apps/server/git/simple-git-branch-manager.test.ts

@@ -5,7 +5,7 @@
  * a project's default branch.
  */
 
-import { describe, it, expect, beforeEach, afterEach } from 'vitest';
+import { describe, it, expect, beforeEach, afterEach, beforeAll, afterAll } from 'vitest';
 import { mkdtemp, rm, writeFile } from 'node:fs/promises';
 import { tmpdir } from 'node:os';
 import path from 'node:path';
@@ -133,14 +133,14 @@ describe('SimpleGitBranchManager', () => {
   let cleanup: () => Promise<void>;
   let branchManager: SimpleGitBranchManager;
 
-  beforeEach(async () => {
+  beforeAll(async () => {
     const setup = await createTestRepoWithRemote();
     clonePath = setup.clonePath;
     cleanup = setup.cleanup;
     branchManager = new SimpleGitBranchManager();
   });
 
-  afterEach(async () => {
+  afterAll(async () => {
     await cleanup();
   });
 
@@ -177,14 +177,14 @@ describe('SimpleGitBranchManager - diffBranchesStat and diffFileSingle', () => {
   let cleanup: () => Promise<void>;
   let branchManager: SimpleGitBranchManager;
 
-  beforeEach(async () => {
+  beforeAll(async () => {
     const setup = await createTestRepoForDiff();
     clonePath = setup.clonePath;
     cleanup = setup.cleanup;
     branchManager = new SimpleGitBranchManager();
   });
 
-  afterEach(async () => {
+  afterAll(async () => {
     await cleanup();
   });