feat(06-03): add coordination tRPC procedures

- Add coordinationManager to TRPCContext and CreateContextOptions
- Add requireCoordinationManager helper function
- Add queueMerge mutation for queuing tasks for merge
- Add processMerges mutation for processing merges in dependency order
- Add getMergeQueueStatus query for queue state inspection
- Add getNextMergeable query for next mergeable task

src/trpc/context.ts

@@ -10,6 +10,7 @@ import type { AgentManager } from '../agent/types.js';
 import type { TaskRepository } from '../db/repositories/task-repository.js';
 import type { MessageRepository } from '../db/repositories/message-repository.js';
 import type { DispatchManager } from '../dispatch/types.js';
+import type { CoordinationManager } from '../coordination/types.js';
 
 // Re-export for convenience
 export type { EventBus, DomainEvent };
@@ -32,6 +33,8 @@ export interface TRPCContext {
   messageRepository?: MessageRepository;
   /** Dispatch manager for task queue operations (optional until server wiring complete) */
   dispatchManager?: DispatchManager;
+  /** Coordination manager for merge queue operations (optional until server wiring complete) */
+  coordinationManager?: CoordinationManager;
 }
 
 /**
@@ -45,6 +48,7 @@ export interface CreateContextOptions {
   taskRepository?: TaskRepository;
   messageRepository?: MessageRepository;
   dispatchManager?: DispatchManager;
+  coordinationManager?: CoordinationManager;
 }
 
 /**
@@ -62,5 +66,6 @@ export function createContext(options: CreateContextOptions): TRPCContext {
     taskRepository: options.taskRepository,
     messageRepository: options.messageRepository,
     dispatchManager: options.dispatchManager,
+    coordinationManager: options.coordinationManager,
   };
 }

src/trpc/router.ts

@@ -12,6 +12,7 @@ import type { AgentInfo, AgentResult } from '../agent/types.js';
 import type { TaskRepository } from '../db/repositories/task-repository.js';
 import type { MessageRepository } from '../db/repositories/message-repository.js';
 import type { DispatchManager } from '../dispatch/types.js';
+import type { CoordinationManager } from '../coordination/types.js';
 
 /**
  * Initialize tRPC with our context type.
@@ -218,6 +219,19 @@ function requireDispatchManager(ctx: TRPCContext): DispatchManager {
   return ctx.dispatchManager;
 }
 
+/**
+ * Helper to ensure coordinationManager is available in context.
+ */
+function requireCoordinationManager(ctx: TRPCContext): CoordinationManager {
+  if (!ctx.coordinationManager) {
+    throw new TRPCError({
+      code: 'INTERNAL_SERVER_ERROR',
+      message: 'Coordination manager not available',
+    });
+  }
+  return ctx.coordinationManager;
+}
+
 // =============================================================================
 // Application Router with Procedures
 // =============================================================================
@@ -245,6 +259,10 @@ function requireDispatchManager(ctx: TRPCContext): DispatchManager {
  * - dispatchNext: Dispatch next available task
  * - getQueueState: Get dispatch queue state
  * - completeTask: Mark a task as complete
+ * - queueMerge: Queue a completed task for merge
+ * - processMerges: Process all ready merges in dependency order
+ * - getMergeQueueStatus: Get merge queue status
+ * - getNextMergeable: Get next task ready to merge
  */
 export const appRouter = router({
   /**
@@ -565,6 +583,56 @@ export const appRouter = router({
       await dispatchManager.completeTask(input.taskId);
       return { success: true };
     }),
+
+  // ===========================================================================
+  // Coordination Procedures
+  // ===========================================================================
+
+  /**
+   * Queue a completed task for merge.
+   * Task will be merged when all dependencies complete.
+   */
+  queueMerge: publicProcedure
+    .input(z.object({ taskId: z.string().min(1) }))
+    .mutation(async ({ ctx, input }) => {
+      const coordinationManager = requireCoordinationManager(ctx);
+      await coordinationManager.queueMerge(input.taskId);
+      return { success: true };
+    }),
+
+  /**
+   * Process all ready merges in dependency order.
+   * Returns results of all merge operations.
+   */
+  processMerges: publicProcedure
+    .input(z.object({
+      targetBranch: z.string().default('main'),
+    }))
+    .mutation(async ({ ctx, input }) => {
+      const coordinationManager = requireCoordinationManager(ctx);
+      const results = await coordinationManager.processMerges(input.targetBranch);
+      return { results };
+    }),
+
+  /**
+   * Get merge queue status.
+   * Shows queued, in-progress, merged, and conflicted tasks.
+   */
+  getMergeQueueStatus: publicProcedure
+    .query(async ({ ctx }) => {
+      const coordinationManager = requireCoordinationManager(ctx);
+      return coordinationManager.getQueueState();
+    }),
+
+  /**
+   * Get next task ready to merge.
+   * Returns task with all dependencies resolved.
+   */
+  getNextMergeable: publicProcedure
+    .query(async ({ ctx }) => {
+      const coordinationManager = requireCoordinationManager(ctx);
+      return coordinationManager.getNextMergeable();
+    }),
 });
 
 /**