feat(05-02): add task tRPC procedures

- Add TaskRepository to TRPCContext (optional, same pattern as AgentManager)
- Add requireTaskRepository helper function
- Add listTasks procedure (query tasks by planId, ordered by order field)
- Add getTask procedure (get single task by ID, throws NOT_FOUND)
- Add updateTaskStatus procedure (update task status to pending/in_progress/completed/blocked)

src/trpc/context.ts

@@ -7,6 +7,7 @@
 
 import type { EventBus, DomainEvent } from '../events/types.js';
 import type { AgentManager } from '../agent/types.js';
+import type { TaskRepository } from '../db/repositories/task-repository.js';
 
 // Re-export for convenience
 export type { EventBus, DomainEvent };
@@ -23,6 +24,8 @@ export interface TRPCContext {
   processCount: number;
   /** Agent manager for agent lifecycle operations (optional until server wiring complete) */
   agentManager?: AgentManager;
+  /** Task repository for task CRUD operations (optional until server wiring complete) */
+  taskRepository?: TaskRepository;
 }
 
 /**
@@ -33,6 +36,7 @@ export interface CreateContextOptions {
   serverStartedAt: Date | null;
   processCount: number;
   agentManager?: AgentManager;
+  taskRepository?: TaskRepository;
 }
 
 /**
@@ -47,5 +51,6 @@ export function createContext(options: CreateContextOptions): TRPCContext {
     serverStartedAt: options.serverStartedAt,
     processCount: options.processCount,
     agentManager: options.agentManager,
+    taskRepository: options.taskRepository,
   };
 }

src/trpc/router.ts

@@ -9,6 +9,7 @@ import { initTRPC, TRPCError } from '@trpc/server';
 import { z } from 'zod';
 import type { TRPCContext } from './context.js';
 import type { AgentInfo, AgentResult } from '../agent/types.js';
+import type { TaskRepository } from '../db/repositories/task-repository.js';
 
 /**
  * Initialize tRPC with our context type.
@@ -176,6 +177,19 @@ function requireAgentManager(ctx: TRPCContext) {
   return ctx.agentManager;
 }
 
+/**
+ * Helper to ensure taskRepository is available in context.
+ */
+function requireTaskRepository(ctx: TRPCContext): TaskRepository {
+  if (!ctx.taskRepository) {
+    throw new TRPCError({
+      code: 'INTERNAL_SERVER_ERROR',
+      message: 'Task repository not available',
+    });
+  }
+  return ctx.taskRepository;
+}
+
 // =============================================================================
 // Application Router with Procedures
 // =============================================================================
@@ -193,6 +207,9 @@ function requireAgentManager(ctx: TRPCContext) {
  * - getAgentByName: Get agent by name
  * - resumeAgent: Resume an agent waiting for input
  * - getAgentResult: Get result of agent's work
+ * - listTasks: List tasks for a plan
+ * - getTask: Get task by ID
+ * - updateTaskStatus: Update task status
  */
 export const appRouter = router({
   /**
@@ -323,6 +340,61 @@ export const appRouter = router({
       const agent = await resolveAgent(ctx, input);
       return agentManager.getResult(agent.id);
     }),
+
+  // ===========================================================================
+  // Task Procedures
+  // ===========================================================================
+
+  /**
+   * List tasks for a plan.
+   * Returns tasks ordered by order field.
+   */
+  listTasks: publicProcedure
+    .input(z.object({ planId: z.string().min(1) }))
+    .query(async ({ ctx, input }) => {
+      const taskRepository = requireTaskRepository(ctx);
+      return taskRepository.findByPlanId(input.planId);
+    }),
+
+  /**
+   * Get a task by ID.
+   * Throws NOT_FOUND if task doesn't exist.
+   */
+  getTask: publicProcedure
+    .input(z.object({ id: z.string().min(1) }))
+    .query(async ({ ctx, input }) => {
+      const taskRepository = requireTaskRepository(ctx);
+      const task = await taskRepository.findById(input.id);
+      if (!task) {
+        throw new TRPCError({
+          code: 'NOT_FOUND',
+          message: `Task '${input.id}' not found`,
+        });
+      }
+      return task;
+    }),
+
+  /**
+   * Update a task's status.
+   * Returns the updated task.
+   */
+  updateTaskStatus: publicProcedure
+    .input(z.object({
+      id: z.string().min(1),
+      status: z.enum(['pending', 'in_progress', 'completed', 'blocked']),
+    }))
+    .mutation(async ({ ctx, input }) => {
+      const taskRepository = requireTaskRepository(ctx);
+      // Check task exists first
+      const existing = await taskRepository.findById(input.id);
+      if (!existing) {
+        throw new TRPCError({
+          code: 'NOT_FOUND',
+          message: `Task '${input.id}' not found`,
+        });
+      }
+      return taskRepository.update(input.id, { status: input.status });
+    }),
 });
 
 /**