Refactor core/ into logical sub-packages and split filter files

Reorganize the flat core/ directory (17 files) into three sub-packages:
- core/devices/ — LED device communication (led_client, wled/adalight clients, providers, DDP)
- core/processing/ — target processing pipeline (processor_manager, target processors, live streams, settings)
- core/capture/ — screen capture & calibration (screen_capture, calibration, pixel_processor, overlay)

Also split the monolithic filters/builtin.py (460 lines, 8 filters) into
individual files: brightness, saturation, gamma, downscaler, pixelate,
auto_crop, flip, color_correction.

Includes the ProcessorManager refactor from target-centric architecture:
ProcessorManager slimmed from ~1600 to ~490 lines with unified
_processors dict replacing duplicate _targets/_kc_targets dicts.

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

server/src/wled_controller/storage/device_store.py

@@ -6,7 +6,7 @@ from datetime import datetime
 from pathlib import Path
 from typing import Dict, List, Optional
 
-from wled_controller.core.calibration import (
+from wled_controller.core.capture.calibration import (
     CalibrationConfig,
     calibration_from_dict,
     calibration_to_dict,
@@ -34,6 +34,7 @@ class Device:
         device_type: str = "wled",
         baud_rate: Optional[int] = None,
         software_brightness: int = 255,
+        auto_shutdown: bool = False,
         calibration: Optional[CalibrationConfig] = None,
         created_at: Optional[datetime] = None,
         updated_at: Optional[datetime] = None,
@@ -46,6 +47,7 @@ class Device:
         self.device_type = device_type
         self.baud_rate = baud_rate
         self.software_brightness = software_brightness
+        self.auto_shutdown = auto_shutdown
         self.calibration = calibration or create_default_calibration(led_count)
         self.created_at = created_at or datetime.utcnow()
         self.updated_at = updated_at or datetime.utcnow()
@@ -67,6 +69,8 @@ class Device:
             d["baud_rate"] = self.baud_rate
         if self.software_brightness != 255:
             d["software_brightness"] = self.software_brightness
+        if self.auto_shutdown:
+            d["auto_shutdown"] = True
         return d
 
     @classmethod
@@ -92,6 +96,7 @@ class Device:
             device_type=data.get("device_type", "wled"),
             baud_rate=data.get("baud_rate"),
             software_brightness=data.get("software_brightness", 255),
+            auto_shutdown=data.get("auto_shutdown", False),
             calibration=calibration,
             created_at=datetime.fromisoformat(data.get("created_at", datetime.utcnow().isoformat())),
             updated_at=datetime.fromisoformat(data.get("updated_at", datetime.utcnow().isoformat())),
@@ -178,6 +183,7 @@ class DeviceStore:
         device_type: str = "wled",
         baud_rate: Optional[int] = None,
         calibration: Optional[CalibrationConfig] = None,
+        auto_shutdown: bool = False,
     ) -> Device:
         """Create a new device."""
         device_id = f"device_{uuid.uuid4().hex[:8]}"
@@ -190,6 +196,7 @@ class DeviceStore:
             device_type=device_type,
             baud_rate=baud_rate,
             calibration=calibration,
+            auto_shutdown=auto_shutdown,
         )
 
         self._devices[device_id] = device
@@ -215,6 +222,7 @@ class DeviceStore:
         enabled: Optional[bool] = None,
         baud_rate: Optional[int] = None,
         calibration: Optional[CalibrationConfig] = None,
+        auto_shutdown: Optional[bool] = None,
     ) -> Device:
         """Update device."""
         device = self._devices.get(device_id)
@@ -232,6 +240,8 @@ class DeviceStore:
             device.enabled = enabled
         if baud_rate is not None:
             device.baud_rate = baud_rate
+        if auto_shutdown is not None:
+            device.auto_shutdown = auto_shutdown
         if calibration is not None:
             if calibration.get_total_leds() != device.led_count:
                 raise ValueError(

server/src/wled_controller/storage/picture_target_store.py

@@ -6,7 +6,7 @@ from datetime import datetime
 from pathlib import Path
 from typing import Dict, List, Optional
 
-from wled_controller.core.processor_manager import ProcessingSettings
+from wled_controller.core.processing.processing_settings import ProcessingSettings
 from wled_controller.storage.picture_target import PictureTarget
 from wled_controller.storage.wled_picture_target import WledPictureTarget
 from wled_controller.storage.key_colors_picture_target import (

server/src/wled_controller/storage/wled_picture_target.py

@@ -4,7 +4,7 @@ from dataclasses import dataclass, field
 from datetime import datetime
 from typing import Optional
 
-from wled_controller.core.processor_manager import ProcessingSettings
+from wled_controller.core.processing.processing_settings import ProcessingSettings
 from wled_controller.storage.picture_target import PictureTarget
 
 
@@ -37,7 +37,7 @@ class WledPictureTarget(PictureTarget):
     @classmethod
     def from_dict(cls, data: dict) -> "WledPictureTarget":
         """Create from dictionary."""
-        from wled_controller.core.processor_manager import DEFAULT_STATE_CHECK_INTERVAL
+        from wled_controller.core.processing.processing_settings import DEFAULT_STATE_CHECK_INTERVAL
 
         settings_data = data.get("settings", {})
         settings = ProcessingSettings(