M5-T04: add Modbus poll service and APScheduler polling job

app/main.py

@@ -25,6 +25,7 @@ from app.config import get_settings
 from app.services.auth import AuthBootstrapError, initialize_auth_schema
 from app.services.config_page import seed_missing_config_from_bootstrap, sync_app_hostname_from_bootstrap
 from app.services.public_ip import check_public_ipv4_and_notify
+from app.services.modbus_poll import poll_all_enabled_devices, BASE_POLL_TICK_SECONDS
 from scripts.app_db_adopt import AppDatabaseAdoptionError, validate_app_runtime_db
 
 logger = logging.getLogger(__name__)
@@ -48,6 +49,15 @@ def _run_scheduled_public_ip_check() -> None:
         session.close()
 
 
+def _run_scheduled_modbus_poll() -> None:
+    session_local = get_session_local()
+    session: Session = session_local()
+    try:
+        poll_all_enabled_devices(session, bootstrap_settings=get_settings())
+    finally:
+        session.close()
+
+
 def ensure_auth_db_ready() -> None:
     session_local = get_session_local()
     session: Session = session_local()
@@ -83,6 +93,14 @@ async def lifespan(_: FastAPI):
         max_instances=1,
         coalesce=True,
     )
+    scheduler.add_job(
+        _run_scheduled_modbus_poll,
+        trigger=IntervalTrigger(seconds=BASE_POLL_TICK_SECONDS),
+        id="modbus-poll",
+        replace_existing=True,
+        max_instances=1,
+        coalesce=True,
+    )
     scheduler.start()
     yield
     scheduler.shutdown(wait=False)