feat: add comprehensive integration tests for auto-mode-service

- Created git-test-repo helper for managing test git repositories
- Added 13 integration tests covering:
  - Worktree operations (create, error handling, non-worktree mode)
  - Feature execution (status updates, model selection, duplicate prevention)
  - Auto loop (start/stop, pending features, max concurrency, events)
  - Error handling (provider errors, continue after failures)
- Integration tests use real git operations with temporary repos
- All 416 tests passing with 72.65% overall coverage
- Service coverage improved: agent-service 58%, auto-mode-service 44%, feature-loader 66%

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

apps/server/vitest.config.ts

@@ -0,0 +1,37 @@
+import { defineConfig } from "vitest/config";
+import path from "path";
+
+export default defineConfig({
+  test: {
+    reporters: ['verbose'],
+    globals: true,
+    environment: "node",
+    setupFiles: ["./tests/setup.ts"],
+    coverage: {
+      provider: "v8",
+      reporter: ["text", "json", "html", "lcov"],
+      include: ["src/**/*.ts"],
+      exclude: [
+        "src/**/*.d.ts",
+        "src/index.ts",
+        "src/routes/**", // Routes are better tested with integration tests
+      ],
+      thresholds: {
+        lines: 80,
+        functions: 80,
+        branches: 75,
+        statements: 80,
+      },
+    },
+    include: ["tests/**/*.test.ts", "tests/**/*.spec.ts"],
+    exclude: ["**/node_modules/**", "**/dist/**"],
+    mockReset: true,
+    restoreMocks: true,
+    clearMocks: true,
+  },
+  resolve: {
+    alias: {
+      "@": path.resolve(__dirname, "./src"),
+    },
+  },
+});