feat(06-01): add coordination domain events for merge lifecycle

- MergeQueuedEvent: completed task queued for merge
- MergeStartedEvent: merge attempt begins
- MergeCompletedEvent: merge succeeds
- MergeConflictedEvent: merge has conflicts (triggers bounce-back)

src/events/index.ts

@@ -29,6 +29,10 @@ export type {
   TaskDispatchedEvent,
   TaskCompletedEvent,
   TaskBlockedEvent,
+  MergeQueuedEvent,
+  MergeStartedEvent,
+  MergeCompletedEvent,
+  MergeConflictedEvent,
   DomainEventMap,
   DomainEventType,
 } from './types.js';

src/events/types.ts

@@ -228,6 +228,51 @@ export interface TaskBlockedEvent extends DomainEvent {
   };
 }
 
+/**
+ * Merge Coordination Events
+ */
+
+export interface MergeQueuedEvent extends DomainEvent {
+  type: 'merge:queued';
+  payload: {
+    taskId: string;
+    agentId: string;
+    worktreeId: string;
+    priority: 'low' | 'medium' | 'high';
+  };
+}
+
+export interface MergeStartedEvent extends DomainEvent {
+  type: 'merge:started';
+  payload: {
+    taskId: string;
+    agentId: string;
+    worktreeId: string;
+    targetBranch: string;
+  };
+}
+
+export interface MergeCompletedEvent extends DomainEvent {
+  type: 'merge:completed';
+  payload: {
+    taskId: string;
+    agentId: string;
+    worktreeId: string;
+    targetBranch: string;
+  };
+}
+
+export interface MergeConflictedEvent extends DomainEvent {
+  type: 'merge:conflicted';
+  payload: {
+    taskId: string;
+    agentId: string;
+    worktreeId: string;
+    targetBranch: string;
+    conflictingFiles: string[];
+  };
+}
+
 /**
  * Union of all domain events - enables type-safe event handling
  */
@@ -250,7 +295,11 @@ export type DomainEventMap =
   | TaskQueuedEvent
   | TaskDispatchedEvent
   | TaskCompletedEvent
-  | TaskBlockedEvent;
+  | TaskBlockedEvent
+  | MergeQueuedEvent
+  | MergeStartedEvent
+  | MergeCompletedEvent
+  | MergeConflictedEvent;
 
 /**
  * Event type literal union for type checking