Fix device provider kwargs, camera crash guard, target API, and graph color picker

- Refactor all device providers to use explicit kwargs.get() instead of
  fragile pop-then-passthrough (fixes WLED target start failing with
  unexpected dmx_protocol kwarg)
- Add process-wide camera index registry to prevent concurrent opens of
  the same physical camera which crashes the DSHOW backend on Windows
- Fix OutputTargetResponse validation error when brightness_value_source_id
  is None (coerce to empty string in response and from_dict)
- Replace native <input type="color"> in graph editor with the custom
  color picker popover used throughout the app, positioned via
  getScreenCTM() inside an absolute overlay on .graph-container

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

server/src/wled_controller/core/devices/adalight_provider.py

@@ -13,10 +13,8 @@ class AdalightDeviceProvider(SerialDeviceProvider):
 
     def create_client(self, url: str, **kwargs) -> LEDClient:
         from wled_controller.core.devices.adalight_client import AdalightClient
-
-        led_count = kwargs.pop("led_count", 0)
-        baud_rate = kwargs.pop("baud_rate", None)
-        kwargs.pop("use_ddp", None)  # Not applicable for serial
-        kwargs.pop("send_latency_ms", None)
-        kwargs.pop("rgbw", None)
-        return AdalightClient(url, led_count=led_count, baud_rate=baud_rate)
+        return AdalightClient(
+            url,
+            led_count=kwargs.get("led_count", 0),
+            baud_rate=kwargs.get("baud_rate"),
+        )

server/src/wled_controller/core/devices/ambiled_provider.py

@@ -13,10 +13,8 @@ class AmbiLEDDeviceProvider(SerialDeviceProvider):
 
     def create_client(self, url: str, **kwargs) -> LEDClient:
         from wled_controller.core.devices.ambiled_client import AmbiLEDClient
-
-        led_count = kwargs.pop("led_count", 0)
-        baud_rate = kwargs.pop("baud_rate", None)
-        kwargs.pop("use_ddp", None)
-        kwargs.pop("send_latency_ms", None)
-        kwargs.pop("rgbw", None)
-        return AmbiLEDClient(url, led_count=led_count, baud_rate=baud_rate)
+        return AmbiLEDClient(
+            url,
+            led_count=kwargs.get("led_count", 0),
+            baud_rate=kwargs.get("baud_rate"),
+        )

server/src/wled_controller/core/devices/mock_provider.py

@@ -24,8 +24,11 @@ class MockDeviceProvider(LEDDeviceProvider):
         return {"manual_led_count", "power_control", "brightness_control"}
 
     def create_client(self, url: str, **kwargs) -> LEDClient:
-        kwargs.pop("use_ddp", None)
-        return MockClient(url, **kwargs)
+        return MockClient(
+            url,
+            led_count=kwargs.get("led_count", 0),
+            send_latency_ms=kwargs.get("send_latency_ms", 0),
+        )
 
     async def check_health(self, url: str, http_client, prev_health=None) -> DeviceHealth:
         return DeviceHealth(online=True, latency_ms=0.0, last_checked=datetime.now(timezone.utc))

server/src/wled_controller/core/devices/mqtt_provider.py

@@ -31,7 +31,10 @@ class MQTTDeviceProvider(LEDDeviceProvider):
         return {"manual_led_count"}
 
     def create_client(self, url: str, **kwargs) -> LEDClient:
-        return MQTTLEDClient(url, **kwargs)
+        return MQTTLEDClient(
+            url,
+            led_count=kwargs.get("led_count", 0),
+        )
 
     async def check_health(
         self, url: str, http_client, prev_health=None,

server/src/wled_controller/core/devices/openrgb_provider.py

@@ -30,12 +30,10 @@ class OpenRGBDeviceProvider(LEDDeviceProvider):
         return {"health_check", "auto_restore", "static_color"}
 
     def create_client(self, url: str, **kwargs) -> LEDClient:
-        zone_mode = kwargs.pop("zone_mode", "combined")
-        kwargs.pop("led_count", None)
-        kwargs.pop("baud_rate", None)
-        kwargs.pop("send_latency_ms", None)
-        kwargs.pop("rgbw", None)
-        return OpenRGBLEDClient(url, zone_mode=zone_mode, **kwargs)
+        return OpenRGBLEDClient(
+            url,
+            zone_mode=kwargs.get("zone_mode", "combined"),
+        )
 
     async def check_health(self, url: str, http_client, prev_health=None) -> DeviceHealth:
         return await OpenRGBLEDClient.check_health(url, http_client, prev_health)

server/src/wled_controller/core/devices/wled_provider.py

@@ -53,12 +53,10 @@ class WLEDDeviceProvider(LEDDeviceProvider):
 
     def create_client(self, url: str, **kwargs) -> LEDClient:
         from wled_controller.core.devices.wled_client import WLEDClient
-        kwargs.pop("led_count", None)
-        kwargs.pop("baud_rate", None)
-        kwargs.pop("send_latency_ms", None)
-        kwargs.pop("rgbw", None)
-        kwargs.pop("zone_mode", None)
-        return WLEDClient(url, **kwargs)
+        return WLEDClient(
+            url,
+            use_ddp=kwargs.get("use_ddp", False),
+        )
 
     async def check_health(self, url: str, http_client, prev_health=None) -> DeviceHealth:
         from wled_controller.core.devices.wled_client import WLEDClient

server/src/wled_controller/core/devices/ws_provider.py

@@ -27,7 +27,10 @@ class WSDeviceProvider(LEDDeviceProvider):
         return {"manual_led_count"}
 
     def create_client(self, url: str, **kwargs) -> LEDClient:
-        return WSLEDClient(url, **kwargs)
+        return WSLEDClient(
+            url,
+            led_count=kwargs.get("led_count", 0),
+        )
 
     async def check_health(
         self, url: str, http_client, prev_health=None,