feat: Add delegation tracking MCP tools

Session 374: Task-MCP and Delegation System Integration (Phase 4 & 6)

- Add task_delegations tool: query delegations for a specific task
- Add task_delegation_query tool: query across all tasks by status/backend
- Enhance taskShow() to display recent delegation history
- New delegations.ts module with getRecentDelegations helper

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

src/tools/index.ts

@@ -197,4 +197,29 @@ export const toolDefinitions = [
       required: ['task_id', 'epic_id'],
     },
   },
+
+  // Delegation Tools
+  {
+    name: 'task_delegations',
+    description: 'List delegations for a specific task (quality scores, backends, status)',
+    inputSchema: {
+      type: 'object',
+      properties: {
+        task_id: { type: 'string', description: 'Task ID (e.g., ST-123)' },
+      },
+      required: ['task_id'],
+    },
+  },
+  {
+    name: 'task_delegation_query',
+    description: 'Query delegations across tasks (filter by status, backend)',
+    inputSchema: {
+      type: 'object',
+      properties: {
+        status: { type: 'string', enum: ['pending', 'success', 'failed', 'partial'], description: 'Filter by delegation status' },
+        backend: { type: 'string', description: 'Filter by backend (e.g., grok, haiku)' },
+        limit: { type: 'number', description: 'Max results (default: 20)' },
+      },
+    },
+  },
 ];