Add static color for simple devices, change auto-shutdown to auto-restore

- Add `static_color` capability to Adalight provider with `set_color()` method
- Add `static_color` field to Device model, DeviceState, and API schemas
- Add GET/PUT `/devices/{id}/color` API endpoints
- Change auto-shutdown behavior: restore device to idle state instead of
  powering off (WLED uses snapshot/restore, Adalight sends static color
  or black frame)
- Rename `_auto_shutdown_device_if_idle` to `_restore_device_idle_state`
- Add inline color picker on device cards for devices with static_color
- Add auto_shutdown toggle to device settings modal
- Update labels from "Auto Shutdown" to "Auto Restore" (en + ru)
- Remove backward-compat KC aliases from ProcessorManager
- Align card action buttons to bottom with flex column layout

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

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

@@ -28,6 +28,15 @@ class DeviceUpdate(BaseModel):
     auto_shutdown: Optional[bool] = Field(None, description="Turn off device when server stops")
 
 
+class StaticColorUpdate(BaseModel):
+    """Request to set or clear the static idle color."""
+
+    color: Optional[List[int]] = Field(
+        None,
+        description="RGB color [R, G, B] with values 0-255, or null to clear",
+    )
+
+
 class Calibration(BaseModel):
     """Calibration configuration for pixel-to-LED mapping."""
 
@@ -92,7 +101,8 @@ class DeviceResponse(BaseModel):
     led_count: int = Field(description="Total number of LEDs")
     enabled: bool = Field(description="Whether device is enabled")
     baud_rate: Optional[int] = Field(None, description="Serial baud rate")
-    auto_shutdown: bool = Field(default=False, description="Turn off device when server stops")
+    auto_shutdown: bool = Field(default=False, description="Restore device to idle state when targets stop")
+    static_color: Optional[List[int]] = Field(None, description="Static idle color [R, G, B]")
     capabilities: List[str] = Field(default_factory=list, description="Device type capabilities")
     calibration: Optional[Calibration] = Field(None, description="Calibration configuration")
     created_at: datetime = Field(description="Creation timestamp")