perf: reduce portable build size ~40MB — replace winsdk/wmi, migrate cv2 to Pillow

- Replace winsdk (~35MB) with winrt packages (~2.5MB) for OS notification
  listener. API is identical, 93% size reduction.
- Replace wmi (~3-5MB) with ctypes for monitor names (EnumDisplayDevicesW)
  and camera names (SetupAPI). Zero external dependency.
- Migrate cv2.resize/imencode/LUT to Pillow/numpy in 5 files (filters,
  preview helpers, kc_target_processor). OpenCV only needed for camera
  and video stream now.
- Fix DefWindowProcW ctypes overflow on 64-bit Python (pre-existing bug
  in platform_detector display power listener).
- Fix openLightbox import in streams-capture-templates.ts (was using
  broken window cast instead of direct import).
- Add mandatory data migration policy to CLAUDE.md after silent data
  loss incident from storage file rename without migration.

build-dist-windows.sh

@@ -222,9 +222,12 @@ DEPS=(
 
 # Windows-only deps
 WIN_DEPS=(
-    "wmi>=1.5.1"
     "PyAudioWPatch>=0.2.12"
-    "winsdk>=1.0.0b10"
+    "winrt-Windows.UI.Notifications>=3.0.0"
+    "winrt-Windows.UI.Notifications.Management>=3.0.0"
+    "winrt-Windows.Foundation>=3.0.0"
+    "winrt-Windows.Foundation.Collections>=3.0.0"
+    "winrt-Windows.ApplicationModel>=3.0.0"
 )
 
 # Download cross-platform deps (prefer binary, allow source for pure Python)
@@ -313,8 +316,8 @@ rm -rf "$SITE_PACKAGES/numpy/_pyinstaller" 2>/dev/null || true
 # Pillow: remove unused image plugins' test data
 rm -rf "$SITE_PACKAGES/PIL/tests" 2>/dev/null || true
 
-# winsdk: remove type stubs and unused namespaces
-find "$SITE_PACKAGES/winsdk" -name "*.pyi" -delete 2>/dev/null || true
+# winrt: remove type stubs
+find "$SITE_PACKAGES/winrt" -name "*.pyi" -delete 2>/dev/null || true
 
 # Remove wled_controller if it got installed
 rm -rf "$SITE_PACKAGES"/wled_controller* "$SITE_PACKAGES"/wled*.dist-info 2>/dev/null || true