feat: HA light target live color preview — per-entity swatches via WebSocket

- Cache per-entity colors in HALightTargetProcessor._update_lights()
- Broadcast colors_update to WS clients at target's update_rate
- WS endpoint: /api/v1/output-targets/{target_id}/ha-light/ws
- Frontend: connect WS when target runs, update swatch colors live
- Card shows colored boxes per mapped entity with entity name labels

server/src/wled_controller/api/schemas/output_targets.py

@@ -18,42 +18,6 @@ class KeyColorRectangleSchema(BaseModel):
     height: float = Field(default=1.0, description="Height (0.0-1.0)", gt=0.0, le=1.0)
 
 
-class KeyColorsSettingsSchema(BaseModel):
-    """Settings for key colors extraction."""
-
-    fps: int = Field(default=10, description="Extraction rate (1-60)", ge=1, le=60)
-    interpolation_mode: str = Field(
-        default="average", description="Color mode (average, median, dominant)"
-    )
-    smoothing: float = Field(
-        default=0.3, description="Temporal smoothing (0.0-1.0)", ge=0.0, le=1.0
-    )
-    pattern_template_id: str = Field(
-        default="", description="Pattern template ID for rectangle layout"
-    )
-    brightness: float = Field(
-        default=1.0, description="Output brightness (0.0-1.0)", ge=0.0, le=1.0
-    )
-    brightness_value_source_id: str = Field(default="", description="Brightness value source ID")
-
-
-class ExtractedColorResponse(BaseModel):
-    """A single extracted color."""
-
-    r: int = Field(description="Red (0-255)")
-    g: int = Field(description="Green (0-255)")
-    b: int = Field(description="Blue (0-255)")
-    hex: str = Field(description="Hex color (#rrggbb)")
-
-
-class KeyColorsResponse(BaseModel):
-    """Extracted key colors for a target."""
-
-    target_id: str = Field(description="Target ID")
-    colors: Dict[str, ExtractedColorResponse] = Field(description="Rectangle name -> color")
-    timestamp: Optional[datetime] = Field(None, description="Extraction timestamp")
-
-
 class HALightMappingSchema(BaseModel):
     """Maps an LED range to one HA light entity."""
 
@@ -69,7 +33,7 @@ class OutputTargetCreate(BaseModel):
     """Request to create an output target."""
 
     name: str = Field(description="Target name", min_length=1, max_length=100)
-    target_type: str = Field(default="led", description="Target type (led, key_colors, ha_light)")
+    target_type: str = Field(default="led", description="Target type (led, ha_light)")
     # LED target fields
     device_id: str = Field(default="", description="LED device ID")
     color_strip_source_id: str = Field(default="", description="Color strip source ID")
@@ -101,13 +65,6 @@ class OutputTargetCreate(BaseModel):
         pattern="^(ddp|http)$",
         description="Send protocol: ddp (UDP) or http (JSON API)",
     )
-    # KC target fields
-    picture_source_id: str = Field(
-        default="", description="Picture source ID (for key_colors targets)"
-    )
-    key_colors_settings: Optional[KeyColorsSettingsSchema] = Field(
-        None, description="Key colors settings (for key_colors targets)"
-    )
     # HA light target fields
     ha_source_id: str = Field(
         default="", description="Home Assistant source ID (for ha_light targets)"
@@ -157,13 +114,6 @@ class OutputTargetUpdate(BaseModel):
     protocol: Optional[str] = Field(
         None, pattern="^(ddp|http)$", description="Send protocol: ddp (UDP) or http (JSON API)"
     )
-    # KC target fields
-    picture_source_id: Optional[str] = Field(
-        None, description="Picture source ID (for key_colors targets)"
-    )
-    key_colors_settings: Optional[KeyColorsSettingsSchema] = Field(
-        None, description="Key colors settings (for key_colors targets)"
-    )
     # HA light target fields
     ha_source_id: Optional[str] = Field(
         None, description="Home Assistant source ID (for ha_light targets)"
@@ -206,11 +156,6 @@ class OutputTargetResponse(BaseModel):
         default=False, description="Auto-reduce FPS when device is unresponsive"
     )
     protocol: str = Field(default="ddp", description="Send protocol (ddp or http)")
-    # KC target fields
-    picture_source_id: str = Field(default="", description="Picture source ID (key_colors)")
-    key_colors_settings: Optional[KeyColorsSettingsSchema] = Field(
-        None, description="Key colors settings"
-    )
     # HA light target fields
     ha_source_id: str = Field(default="", description="Home Assistant source ID (ha_light)")
     ha_light_mappings: Optional[List[HALightMappingSchema]] = Field(
@@ -263,12 +208,6 @@ class TargetProcessingState(BaseModel):
     timing_audio_render_ms: Optional[float] = Field(
         None, description="Audio visualization render time (ms)"
     )
-    timing_calc_colors_ms: Optional[float] = Field(
-        None, description="Color calculation time (ms, KC targets)"
-    )
-    timing_broadcast_ms: Optional[float] = Field(
-        None, description="WebSocket broadcast time (ms, KC targets)"
-    )
     display_index: Optional[int] = Field(None, description="Current display index")
     overlay_active: bool = Field(
         default=False, description="Whether visualization overlay is active"
@@ -328,25 +267,3 @@ class BulkTargetResponse(BaseModel):
     errors: Dict[str, str] = Field(
         default_factory=dict, description="Map of target ID to error message for failures"
     )
-
-
-class KCTestRectangleResponse(BaseModel):
-    """A rectangle with its extracted color from a KC test."""
-
-    name: str = Field(description="Rectangle name")
-    x: float = Field(description="Left edge (0.0-1.0)")
-    y: float = Field(description="Top edge (0.0-1.0)")
-    width: float = Field(description="Width (0.0-1.0)")
-    height: float = Field(description="Height (0.0-1.0)")
-    color: ExtractedColorResponse = Field(description="Extracted color for this rectangle")
-
-
-class KCTestResponse(BaseModel):
-    """Response from testing a KC target."""
-
-    image: str = Field(description="Base64 data URI of the captured frame")
-    rectangles: List[KCTestRectangleResponse] = Field(
-        description="Rectangles with extracted colors"
-    )
-    interpolation_mode: str = Field(description="Color extraction mode used")
-    pattern_template_name: str = Field(description="Pattern template name")