Show edge test colors on LED device when overlay is active

Lights up device LEDs with calibration edge colors (top=red, right=green,
bottom=blue, left=yellow) when the overlay is started, and clears them when
the overlay is stopped. Skips if the target is currently processing.

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

server/src/wled_controller/core/processing/processor_manager.py

@@ -453,16 +453,38 @@ class ProcessorManager:
 
     # ===== OVERLAY VISUALIZATION (delegates to processor) =====
 
+    # Default edge colors for overlay LED test (same as frontend EDGE_TEST_COLORS)
+    _OVERLAY_EDGE_COLORS = {
+        "top": [255, 0, 0],
+        "right": [0, 255, 0],
+        "bottom": [0, 100, 255],
+        "left": [255, 255, 0],
+    }
+
     async def start_overlay(self, target_id: str, target_name: str = None) -> None:
         proc = self._get_processor(target_id)
         if not proc.supports_overlay():
             raise ValueError(f"Target {target_id} does not support overlays")
         await proc.start_overlay(target_name)
 
+        # Light up device LEDs with edge test colors while overlay is visible
+        if isinstance(proc, WledTargetProcessor) and not proc.is_running:
+            try:
+                await self.set_test_mode(proc.device_id, self._OVERLAY_EDGE_COLORS)
+            except Exception as e:
+                logger.warning(f"Failed to set edge test for overlay on {proc.device_id}: {e}")
+
     async def stop_overlay(self, target_id: str) -> None:
         proc = self._get_processor(target_id)
         await proc.stop_overlay()
 
+        # Clear device LEDs when overlay is dismissed
+        if isinstance(proc, WledTargetProcessor) and not proc.is_running:
+            try:
+                await self.set_test_mode(proc.device_id, {})
+            except Exception as e:
+                logger.warning(f"Failed to clear edge test after overlay on {proc.device_id}: {e}")
+
     def is_overlay_active(self, target_id: str) -> bool:
         return self._get_processor(target_id).is_overlay_active()