step 3.4 complete: agent run orchestrator — local/cloud runner + trigger_pending_runs + 23 tests

AI_REFACTOR_PLAN.md

@@ -375,7 +375,7 @@ Cloud Agent:
 - **Outcome:** Backend maintains persistent WS connections to Electron devices for agent triggers.
 
 ### Step 3.4 — Agent run orchestrator
-- [ ] Create `app/core/agent_runner.py`:
+- [x] Create `app/core/agent_runner.py`:
   - `async run_local_agent(user_id, config: LocalAgentConfig, device_mgr: DeviceConnectionManager)`:
     1. Check device is online with matching `device_id` → abort if offline
     2. Create `AgentRunLog` with `status=running`
@@ -404,8 +404,12 @@ Cloud Agent:
     - For cloud agents: triggers regardless of device (any connected device can receive results)
     - Executes runs sequentially (one at a time to avoid overwhelming the WS)
   - Error handling: on any failure, update `AgentRunLog` with `status=error` + error details
-- **Files:** `app/core/agent_runner.py`
-- **Outcome:** Backend drives all agent execution — both local (via WS file request) and cloud (direct API calls).
+- [x] Wire `POST /agents/{id}/run` endpoint to dispatch background task via `asyncio.create_task()`
+- [x] Replace `_trigger_pending_runs_stub` in `device_ws.py` with real `trigger_pending_runs` call
+- [x] Add `croniter>=3.0.0` to `requirements.txt`
+- [x] 23 unit + integration tests covering all code paths
+- **Files:** `app/core/agent_runner.py`, `app/api/routes/agents.py`, `app/api/routes/device_ws.py`, `requirements.txt`, `tests/test_agent_runner.py`
+- **Outcome:** Backend drives all agent execution — both local (via WS file request) and cloud (direct API calls — stub until Step 3.6).
 
 ### Step 3.5 — Chatbot Journey endpoint
 - [ ] Create `app/api/routes/agent_setup.py`: