fix: always send device config on save — sync toggle now works both ways

modules/app_device_config.py

@@ -36,10 +36,14 @@ def update_device_config(body, errors):
         # Allow toggling sync_enabled off
         if "sync_enabled" in body and not body["sync_enabled"]:
             _set_sync_enabled(False)
-            # Toggling off is always allowed — don't return error even if
-            # other locked fields are in the body (the JS always sends them).
+            # Toggling off is always allowed — don't error on locked fields
+            # (the JS always sends them alongside the toggle).
             return errors
-        # User cannot edit locked fields while syncing from server.
+        # Sync is staying enabled — locked fields are ignored silently.
+        # The JS always sends them; rejecting would break the save flow.
+        if "sync_enabled" in body and body["sync_enabled"]:
+            return errors
+        # User tried to edit locked fields without the sync toggle — reject.
         if any(k in body for k in ["owner_name", "car_model", "avatar_path"]):
             errors["error"] = "Cannot edit device config while server sync is enabled. Server is source of truth."
         return errors

static/js/settings.js

@@ -459,8 +459,7 @@ form.addEventListener('submit', async event => {
         }
         populateRemoteConfig(remoteConfigResult);
 
-        // Save device config (skip if sync is enabled — server is source of truth)
-        if (!fields.deviceSyncEnabled.checked) {
+        // Save device config (always send — backend validates locked fields when sync is on)
         const deviceConfigResponse = await fetch('/api/device-config', {
             method: 'POST',
             headers: {'Content-Type': 'application/json'},
@@ -472,7 +471,6 @@ form.addEventListener('submit', async event => {
             throw new Error(deviceConfigResult.error || `HTTP ${deviceConfigResponse.status}`);
         }
         populateDeviceConfig(deviceConfigResult);
-        }
         
         showMessage('Settings saved.', 'success');
     } catch (error) {