Add OpenRGB per-zone LED control with separate/combined modes and zone preview

- Zone picker UI in device add/settings modals with per-zone checkbox selection
- Combined mode: pixels distributed sequentially across zones
- Separate mode: full effect resampled independently to each zone via linear interpolation
- Per-zone LED preview in target cards: one canvas strip per zone with hover overlay labels
- Zone badges on device cards enriched with actual LED counts from OpenRGB API
- Fix stale led_count by using device_led_count discovered at connect time

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

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

@@ -58,6 +58,8 @@ class DeviceState:
     test_calibration: Optional[CalibrationConfig] = None
     # Tracked power state for serial devices (no hardware query)
     power_on: bool = True
+    # OpenRGB zone mode: "combined" or "separate"
+    zone_mode: str = "combined"
 
 
 class ProcessorManager:
@@ -160,6 +162,7 @@ class ProcessorManager:
             test_mode_active=ds.test_mode_active,
             send_latency_ms=send_latency_ms,
             rgbw=rgbw,
+            zone_mode=ds.zone_mode,
         )
 
     # ===== EVENT SYSTEM (state change notifications) =====
@@ -200,6 +203,7 @@ class ProcessorManager:
         baud_rate: Optional[int] = None,
         software_brightness: int = 255,
         auto_shutdown: bool = False,
+        zone_mode: str = "combined",
     ):
         """Register a device for health monitoring."""
         if device_id in self._devices:
@@ -213,6 +217,7 @@ class ProcessorManager:
             baud_rate=baud_rate,
             software_brightness=software_brightness,
             auto_shutdown=auto_shutdown,
+            zone_mode=zone_mode,
         )
 
         self._devices[device_id] = state

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

@@ -74,6 +74,7 @@ class DeviceInfo:
     test_mode_active: bool = False
     send_latency_ms: int = 0
     rgbw: bool = False
+    zone_mode: str = "combined"
 
 
 @dataclass

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

@@ -65,6 +65,7 @@ class WledTargetProcessor(TargetProcessor):
         self._overlay_active = False
         self._needs_keepalive = True
 
+        self._effective_led_count: int = 0
         self._resolved_display_index: Optional[int] = None
 
         # Fit-to-device linspace cache (per-instance to avoid cross-target thrash)
@@ -106,11 +107,24 @@ class WledTargetProcessor(TargetProcessor):
                 baud_rate=device_info.baud_rate,
                 send_latency_ms=device_info.send_latency_ms,
                 rgbw=device_info.rgbw,
+                zone_mode=device_info.zone_mode,
             )
             await self._led_client.connect()
+
+            # Use client-reported LED count if available (more accurate than stored)
+            client_led_count = self._led_client.device_led_count
+            effective_led_count = client_led_count if client_led_count and client_led_count > 0 else device_info.led_count
+            self._effective_led_count = effective_led_count
+
+            if effective_led_count != device_info.led_count:
+                logger.info(
+                    f"Target {self._target_id}: device reports {effective_led_count} LEDs "
+                    f"(stored: {device_info.led_count}), using actual count"
+                )
+
             logger.info(
                 f"Target {self._target_id} connected to {device_info.device_type} "
-                f"device ({device_info.led_count} LEDs)"
+                f"device ({effective_led_count} LEDs)"
             )
             self._device_state_before = await self._led_client.snapshot_device_state()
             self._needs_keepalive = "standby_required" in get_device_capabilities(device_info.device_type)
@@ -132,8 +146,8 @@ class WledTargetProcessor(TargetProcessor):
 
         try:
             stream = await asyncio.to_thread(css_manager.acquire, self._css_id, self._target_id)
-            if hasattr(stream, "configure") and device_info.led_count > 0:
-                stream.configure(device_info.led_count)
+            if hasattr(stream, "configure") and self._effective_led_count > 0:
+                stream.configure(self._effective_led_count)
             css_manager.notify_target_fps(self._css_id, self._target_id, self._target_fps)
 
             self._resolved_display_index = getattr(stream, "display_index", None)
@@ -254,7 +268,7 @@ class WledTargetProcessor(TargetProcessor):
             return
 
         device_info = self._ctx.get_device_info(self._device_id)
-        device_leds = device_info.led_count if device_info else 0
+        device_leds = getattr(self, '_effective_led_count', None) or (device_info.led_count if device_info else 0)
 
         # Release old stream
         if self._css_stream is not None and old_css_id:
@@ -533,7 +547,7 @@ class WledTargetProcessor(TargetProcessor):
         prev_frame_time_stamp = time.perf_counter()
         loop = asyncio.get_running_loop()
         _init_device_info = self._ctx.get_device_info(self._device_id)
-        _total_leds = _init_device_info.led_count if _init_device_info else 0
+        _total_leds = getattr(self, '_effective_led_count', None) or (_init_device_info.led_count if _init_device_info else 0)
 
         # Stream reference — re-read each tick to detect hot-swaps
         stream = self._css_stream