fix: odometer sync is Pi→Server only — portal displays read-only value from DB

server/app.py

@@ -788,8 +788,27 @@ def api_device_config_push():
     
     Pi pushes local config changes to server. Accepts a partial update:
     any of owner_name, car_model, device_name, avatar_path, odometer_baseline.
+    odometer_baseline is Pi→Server only — the portal cannot edit it.
     """
     body = request.get_json(silent=True) or {}
+    
+    # Handle odometer_baseline separately — Pi→Server only.
+    odometer = body.pop("odometer_baseline", None)
+    if odometer is not None:
+        try:
+            odometer = float(odometer)
+            if odometer < 0 or odometer > 999999:
+                return jsonify(error="Invalid device config.", 
+                               fields={"odometer_baseline": "Must be between 0 and 999,999 km."}), 400
+        except (TypeError, ValueError):
+            return jsonify(error="Invalid device config.",
+                           fields={"odometer_baseline": "Must be a number."}), 400
+        with db.get_cursor(commit=True) as cur:
+            cur.execute(
+                "UPDATE devices SET odometer_baseline = %s, config_version = config_version + 1, config_updated_at = now() WHERE id = %s",
+                (odometer, g.device_id),
+            )
+    
     success, errors = device_config.update_device_config(g.device_id, body)
     if not success:
         return jsonify(error="Invalid device config.", fields=errors), 400