feat(KB-648): enable parallel test execution and optimize test performance

- Optimize backup tests using fake timers instead of real timeouts

- Enable parallel file execution in core, engine, CLI, and dashboard packages

- Add inline test helpers to reduce dependencies in dashboard routes tests

- Update executor tests with exact command matching and improved assertions

- Update AGENTS.md with test optimization patterns (fake timers, unique temp dirs)

packages/engine/src/index.ts

@@ -14,62 +14,3 @@ export { PrCommentHandler } from "./pr-comment-handler.js";
 export { NtfyNotifier, type NtfyNotifierOptions } from "./notifier.js";
 export { CronRunner, type CronRunnerOptions } from "./cron-runner.js";
 export { StuckTaskDetector, type StuckTaskDetectorOptions, type DisposableSession } from "./stuck-task-detector.js";
-
-// ── Project Runtime (Multi-Project Support) ────────────────────────────────
-
-export {
-  type ProjectRuntime,
-  type ProjectRuntimeConfig,
-  type RuntimeStatus,
-  type RuntimeMetrics,
-  type ProjectRuntimeEvents,
-  type GlobalMetrics,
-} from "./project-runtime.js";
-
-export { InProcessRuntime } from "./runtimes/in-process-runtime.js";
-export { ChildProcessRuntime } from "./runtimes/child-process-runtime.js";
-export { ProjectManager, type ProjectManagerEvents } from "./project-manager.js";
-
-// ── IPC Protocol ───────────────────────────────────────────────────────
-
-export {
-  type IpcMessage,
-  type IpcCommandType,
-  type IpcResponseType,
-  type IpcEventType,
-  START_RUNTIME,
-  STOP_RUNTIME,
-  GET_STATUS,
-  GET_METRICS,
-  GET_TASK_STORE,
-  GET_SCHEDULER,
-  PING,
-  OK,
-  ERROR,
-  PONG,
-  TASK_CREATED,
-  TASK_MOVED,
-  TASK_UPDATED,
-  ERROR_EVENT,
-  HEALTH_CHANGED,
-  type StartRuntimePayload,
-  type StopRuntimePayload,
-  type OkPayload,
-  type ErrorPayload,
-  type PongPayload,
-  type TaskCreatedPayload,
-  type TaskMovedPayload,
-  type TaskUpdatedPayload,
-  type ErrorEventPayload,
-  type HealthChangedPayload,
-  isIpcCommand,
-  isIpcResponse,
-  isIpcEvent,
-  createCommand,
-  createResponse,
-  createEvent,
-  generateCorrelationId,
-} from "./ipc/ipc-protocol.js";
-
-export { IpcHost } from "./ipc/ipc-host.js";
-export { IpcWorker } from "./ipc/ipc-worker.js";