feat(settings): server global brightness and Wi-Fi driver resync

- Serve GET /settings as JSON by removing duplicate HTML route (use /settings/page for the standalone UI).

- Save global_brightness via PUT; broadcast to connected drivers; push saved level when outbound WS connects.

- Zones UI loads brightness from GET /settings only (no localStorage).

- Bump led-driver submodule for settings.save on brightness with save flag.

- Extend API doc and endpoint tests for global_brightness.

Co-authored-by: Cursor <cursoragent@cursor.com>

src/controllers/settings.py

@@ -1,7 +1,11 @@
-from microdot import Microdot, send_file
-from settings import Settings
+import asyncio
 import json
 
+from microdot import Microdot, send_file
+
+from models import wifi_ws_clients
+from settings import Settings
+
 controller = Microdot()
 settings = Settings()
 
@@ -63,17 +67,36 @@ def _validate_wifi_channel(value):
     return ch
 
 
+def _validate_global_brightness(value):
+    """Return int 0–255 or raise ValueError."""
+    v = int(value)
+    if v < 0 or v > 255:
+        raise ValueError("global_brightness must be between 0 and 255")
+    return v
+
+
 @controller.put('/settings')
 async def update_settings(request):
     """Update general settings."""
     try:
         data = request.json
+        global_brightness_changed = False
         for key, value in data.items():
             if key == 'wifi_channel' and value is not None:
                 settings[key] = _validate_wifi_channel(value)
+            elif key == 'global_brightness' and value is not None:
+                settings[key] = _validate_global_brightness(value)
+                global_brightness_changed = True
             else:
                 settings[key] = value
         settings.save()
+        if global_brightness_changed:
+            try:
+                asyncio.get_running_loop().create_task(
+                    wifi_ws_clients.broadcast_global_brightness_to_tcp_drivers()
+                )
+            except RuntimeError:
+                pass
         return json.dumps({"message": "Settings updated successfully"}), 200, {'Content-Type': 'application/json'}
     except ValueError as e:
         return json.dumps({"error": str(e)}), 400