feat(run): async refactor — run_live_async + 7-step shutdown

run_live() is now a thin asyncio.run() wrapper. run_live_async():
- Blocking pipeline (capture→canary→detect→_handle_tick→snapshot) in
  asyncio.to_thread() per decision 1 (_sync_detection_tick function)
- TelegramPoller + ScreenshotScheduler as background asyncio tasks
- asyncio.Queue[Command] for inter-task communication
- Auto-start scheduler on PRIMED, auto-stop on fire/cooled/phase_skip
- 7-step graceful shutdown sequence
- heartbeat_due uses time.monotonic() (prevents immediate-fire regression)
- Status command: FSM state, last detection, uptime, fire count, canary health
- "ss" command: one-shot capture+annotate+send via to_thread
- Price overlay in _save_annotated_frame (dot_pos_abs + canary_ok params)
- test_main.py: ScriptedDetector.step(ts, frame=None) for zero regression

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

tests/test_main.py

@@ -186,7 +186,7 @@ def test_run_live_catchup_sell_from_gray_then_dark_red(monkeypatch, tmp_path):
         ]
         def __init__(self, *a, **kw):
             self._i = 0
-        def step(self, ts):
+        def step(self, ts, frame=None):
             if self._i >= len(self._script):
                 raise _StopLoop
             color, accepted = self._script[self._i]