Introduce Picture Targets to separate processing from devices

Add PictureTarget entity that bridges PictureSource to output device,
separating processing settings from device connection/calibration state.
This enables future target types (Art-Net, E1.31) and cleanly decouples
"what to stream" from "where to stream."

- Add PictureTarget/WledPictureTarget dataclasses and storage
- Split ProcessorManager into DeviceState (health) + TargetState (processing)
- Add /api/v1/picture-targets endpoints (CRUD, start/stop, settings, metrics)
- Simplify device API (remove processing/settings/metrics endpoints)
- Auto-migrate existing device settings to picture targets on first startup
- Add Targets tab to WebUI with target cards and editor modal
- Add en/ru locale keys for targets UI

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

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

@@ -0,0 +1,114 @@
+"""Picture target schemas (CRUD, processing state, settings, metrics)."""
+
+from datetime import datetime
+from typing import Dict, List, Literal, Optional
+
+from pydantic import BaseModel, Field
+
+from wled_controller.core.processor_manager import DEFAULT_STATE_CHECK_INTERVAL
+
+
+class ColorCorrection(BaseModel):
+    """Color correction settings."""
+
+    gamma: float = Field(default=2.2, description="Gamma correction", ge=0.1, le=5.0)
+    saturation: float = Field(default=1.0, description="Saturation multiplier", ge=0.0, le=2.0)
+    brightness: float = Field(default=1.0, description="Brightness multiplier", ge=0.0, le=1.0)
+
+
+class ProcessingSettings(BaseModel):
+    """Processing settings for a picture target."""
+
+    display_index: int = Field(default=0, description="Display to capture", ge=0)
+    fps: int = Field(default=30, description="Target frames per second", ge=10, le=90)
+    border_width: int = Field(default=10, description="Border width in pixels", ge=1, le=100)
+    interpolation_mode: str = Field(default="average", description="LED color interpolation mode (average, median, dominant)")
+    brightness: float = Field(default=1.0, description="Global brightness (0.0-1.0)", ge=0.0, le=1.0)
+    smoothing: float = Field(default=0.3, description="Temporal smoothing factor (0.0=none, 1.0=full)", ge=0.0, le=1.0)
+    state_check_interval: int = Field(
+        default=DEFAULT_STATE_CHECK_INTERVAL, ge=5, le=600,
+        description="Seconds between WLED health checks"
+    )
+    color_correction: Optional[ColorCorrection] = Field(
+        default_factory=ColorCorrection,
+        description="Color correction settings"
+    )
+
+
+class PictureTargetCreate(BaseModel):
+    """Request to create a picture target."""
+
+    name: str = Field(description="Target name", min_length=1, max_length=100)
+    target_type: str = Field(default="wled", description="Target type (wled)")
+    device_id: str = Field(default="", description="WLED device ID")
+    picture_source_id: str = Field(default="", description="Picture source ID")
+    settings: Optional[ProcessingSettings] = Field(None, description="Processing settings")
+    description: Optional[str] = Field(None, description="Optional description", max_length=500)
+
+
+class PictureTargetUpdate(BaseModel):
+    """Request to update a picture target."""
+
+    name: Optional[str] = Field(None, description="Target name", min_length=1, max_length=100)
+    device_id: Optional[str] = Field(None, description="WLED device ID")
+    picture_source_id: Optional[str] = Field(None, description="Picture source ID")
+    settings: Optional[ProcessingSettings] = Field(None, description="Processing settings")
+    description: Optional[str] = Field(None, description="Optional description", max_length=500)
+
+
+class PictureTargetResponse(BaseModel):
+    """Picture target response."""
+
+    id: str = Field(description="Target ID")
+    name: str = Field(description="Target name")
+    target_type: str = Field(description="Target type")
+    device_id: str = Field(default="", description="WLED device ID")
+    picture_source_id: str = Field(default="", description="Picture source ID")
+    settings: ProcessingSettings = Field(description="Processing settings")
+    description: Optional[str] = Field(None, description="Description")
+    created_at: datetime = Field(description="Creation timestamp")
+    updated_at: datetime = Field(description="Last update timestamp")
+
+
+class PictureTargetListResponse(BaseModel):
+    """List of picture targets response."""
+
+    targets: List[PictureTargetResponse] = Field(description="List of picture targets")
+    count: int = Field(description="Number of targets")
+
+
+class TargetProcessingState(BaseModel):
+    """Processing state for a picture target."""
+
+    target_id: str = Field(description="Target ID")
+    device_id: str = Field(description="Device ID")
+    processing: bool = Field(description="Whether processing is active")
+    fps_actual: Optional[float] = Field(None, description="Actual FPS achieved")
+    fps_target: int = Field(description="Target FPS")
+    display_index: int = Field(description="Current display index")
+    last_update: Optional[datetime] = Field(None, description="Last successful update")
+    errors: List[str] = Field(default_factory=list, description="Recent errors")
+    wled_online: bool = Field(default=False, description="Whether WLED device is reachable")
+    wled_latency_ms: Optional[float] = Field(None, description="WLED health check latency in ms")
+    wled_name: Optional[str] = Field(None, description="WLED device name")
+    wled_version: Optional[str] = Field(None, description="WLED firmware version")
+    wled_led_count: Optional[int] = Field(None, description="LED count reported by WLED device")
+    wled_rgbw: Optional[bool] = Field(None, description="Whether WLED device uses RGBW LEDs")
+    wled_led_type: Optional[str] = Field(None, description="LED chip type (e.g. WS2812B, SK6812 RGBW)")
+    wled_last_checked: Optional[datetime] = Field(None, description="Last health check time")
+    wled_error: Optional[str] = Field(None, description="Last health check error")
+
+
+class TargetMetricsResponse(BaseModel):
+    """Target metrics response."""
+
+    target_id: str = Field(description="Target ID")
+    device_id: str = Field(description="Device ID")
+    processing: bool = Field(description="Whether processing is active")
+    fps_actual: Optional[float] = Field(None, description="Actual FPS")
+    fps_target: int = Field(description="Target FPS")
+    uptime_seconds: float = Field(description="Processing uptime in seconds")
+    frames_processed: int = Field(description="Total frames processed")
+    errors_count: int = Field(description="Total error count")
+    last_error: Optional[str] = Field(None, description="Last error message")
+    last_update: Optional[datetime] = Field(None, description="Last update timestamp")