feat(14-04): export DefaultPhaseDispatchManager from dispatch module

- Add export for phase dispatch adapter
- Consistent with DefaultDispatchManager export pattern

src/dispatch/index.ts

@@ -9,5 +9,6 @@
 export type { DispatchManager, QueuedTask, DispatchResult } from './types.js';
 export type { PhaseDispatchManager, QueuedPhase, PhaseDispatchResult } from './types.js';
 
-// Adapter implementation
+// Adapter implementations
 export { DefaultDispatchManager } from './manager.js';
+export { DefaultPhaseDispatchManager } from './phase-manager.js';