v2.0.3: CLI client + human inbox + cost tracking + Boomerang new_task

Phase 7 of v2.0. BooCoder gains a terminal-driven UX and subagent
isolation primitive.

CLI (src/cli.ts): standalone entry point for terminal use.
- boocode run "task" [--agent x] [--model y] — create + stream output
- boocode ls [--state x] — formatted task table
- boocode attach <id> — WS stream of running task
- boocode send <id> "msg" — follow-up message to task session
Connects to BOOCODER_URL (default http://100.114.205.53:9502).

Human inbox (routes/inbox.ts): GET /api/inbox (failed/blocked tasks),
POST /api/inbox/:id/retry (reset to pending for re-dispatch).

Cost tracking: dispatcher aggregates tokens_used from all messages in
the task's session after completion, stores in tasks.cost_tokens.
GET /api/stats/costs?group_by=project|agent|day for aggregation.

Boomerang subagent isolation (3 new tools):
- new_task: creates child task with parent_task_id linkage, runs in
  fresh isolated session. Orchestrator sees only output_summary.
- list_tasks: query child tasks of current parent
- check_task_status: read task state + output_summary

The orchestrator pattern: an agent with tools: [new_task, list_tasks,
check_task_status] can ONLY dispatch — can't read files or MCP. This
is the Roo Code Boomerang Tasks capability-restriction principle.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

apps/coder/package.json

@@ -8,6 +8,7 @@
     "dev": "tsx watch src/index.ts",
     "build": "tsc && node -e \"import('node:fs').then(fs=>fs.copyFileSync('src/schema.sql','dist/schema.sql'))\"",
     "start": "node dist/index.js",
+    "cli": "tsx src/cli.ts",
     "typecheck": "tsc --noEmit",
     "test": "vitest run"
   },
@@ -19,10 +20,12 @@
     "@modelcontextprotocol/sdk": "^1.29.0",
     "fastify": "^4.28.1",
     "postgres": "^3.4.4",
+    "ws": "^8.18.0",
     "zod": "^3.23.8"
   },
   "devDependencies": {
     "@types/node": "^20.14.10",
+    "@types/ws": "^8.5.10",
     "tsx": "^4.16.2",
     "typescript": "^5.5.0",
     "vitest": "^3.0.0"