feat: remove state message retrieval and associated SQLite storage

API.md

@@ -795,32 +795,6 @@ Publish a ping message to the MQTT broker for testing.
 
 ---
 
-### Get State Messages
-
-Retrieve stored state messages from SQLite storage.
-
-**Endpoint**: `GET /messages`
-
-**Authentication**: Required
-
-**Query Parameters**:
-- `page`: Page number (default: 0)
-
-**Response** (200 OK):
-```json
-{
-  "messages": [
-    {
-      "id": 1,
-      "payload": "message content",
-      "timestamp": "2026-01-14T10:00:00Z"
-    }
-  ]
-}
-```
-
----
-
 ## MQTT Integration
 
 ### Device Discovery
@@ -963,7 +937,6 @@ password = ""
 4. **UUID Format**: Always use valid UUID v4 format for device, sensor, and actor IDs
 5. **Date Format**: Use RFC3339 format for all timestamp fields
 6. **Device Discovery**: Devices can self-register via MQTT discovery messages
-7. **State Messages**: Messages on topics starting with `state:` are automatically stored
 
 ---