feat: bootstrap dodo phase one

worker/main.py

@@ -0,0 +1,20 @@
+import asyncio
+
+from apscheduler.schedulers.asyncio import AsyncIOScheduler
+
+
+async def scan_due_reminders() -> None:
+    # Reminder delivery is implemented in phase 2. Keeping the scheduler isolated
+    # ensures API restarts never own reminder timing.
+    return None
+
+
+async def main() -> None:
+    scheduler = AsyncIOScheduler(timezone="UTC")
+    scheduler.add_job(scan_due_reminders, "interval", seconds=30, max_instances=1)
+    scheduler.start()
+    await asyncio.Event().wait()
+
+
+if __name__ == "__main__":
+    asyncio.run(main())