added reminder

backend/app/reminders/watcher.py

@@ -0,0 +1,31 @@
+import asyncio
+import logging
+
+from app.config import get_settings
+from app.db.base import SessionLocal
+from app.reminders.fire import check_due_reminders
+
+logger = logging.getLogger(__name__)
+
+WATCH_INTERVAL_SEC = 30
+
+
+async def reminders_watcher_loop() -> None:
+    while True:
+        try:
+            await asyncio.sleep(WATCH_INTERVAL_SEC)
+            if not get_settings().reminders_enabled:
+                continue
+            await _tick()
+        except asyncio.CancelledError:
+            raise
+        except Exception:
+            logger.exception("Reminders watcher error")
+
+
+async def _tick() -> None:
+    db = SessionLocal()
+    try:
+        check_due_reminders(db)
+    finally:
+        db.close()