Add CSPT entity, processed CSS source type, reverse filter, and UI improvements

- Add Color Strip Processing Template (CSPT) entity: reusable filter chains
  for 1D LED strip postprocessing (backend, storage, API, frontend CRUD)
- Add "processed" color strip source type that wraps another CSS source and
  applies a CSPT filter chain (dataclass, stream, schema, modal, cards)
- Add Reverse filter for strip LED order reversal
- Add CSPT and processed CSS nodes/edges to visual graph editor
- Add CSPT test preview WS endpoint with input source selection
- Add device settings CSPT template selector (add + edit modals with hints)
- Use icon grids for palette quantization preset selector in filter lists
- Use EntitySelect for template references and test modal source selectors
- Fix filters.css_filter_template.desc missing localization
- Fix icon grid cell height inequality (grid-auto-rows: 1fr)
- Rename "Processed" subtab to "Processing Templates"
- Localize all new strings (en/ru/zh)

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

server/src/wled_controller/api/routes/output_targets.py

@@ -3,7 +3,6 @@
 import asyncio
 import base64
 import io
-import secrets
 import time
 
 import numpy as np
@@ -35,7 +34,6 @@ from wled_controller.api.schemas.output_targets import (
     TargetMetricsResponse,
     TargetProcessingState,
 )
-from wled_controller.config import get_config
 from wled_controller.core.capture_engines import EngineRegistry
 from wled_controller.core.filters import FilterRegistry, ImagePool
 from wled_controller.core.processing.processor_manager import ProcessorManager
@@ -151,8 +149,9 @@ async def create_target(
     try:
         # Validate device exists if provided
         if data.device_id:
-            device = device_store.get_device(data.device_id)
-            if not device:
+            try:
+                device_store.get_device(data.device_id)
+            except ValueError:
                 raise HTTPException(status_code=422, detail=f"Device {data.device_id} not found")
 
         kc_settings = _kc_schema_to_settings(data.key_colors_settings) if data.key_colors_settings else None
@@ -250,8 +249,9 @@ async def update_target(
     try:
         # Validate device exists if changing
         if data.device_id is not None and data.device_id:
-            device = device_store.get_device(data.device_id)
-            if not device:
+            try:
+                device_store.get_device(data.device_id)
+            except ValueError:
                 raise HTTPException(status_code=422, detail=f"Device {data.device_id} not found")
 
         # Build KC settings with partial-update support: only apply fields that were
@@ -697,16 +697,8 @@ async def target_colors_ws(
     token: str = Query(""),
 ):
     """WebSocket for real-time key color updates. Auth via ?token=<api_key>."""
-    # Authenticate
-    authenticated = False
-    cfg = get_config()
-    if token and cfg.auth.api_keys:
-        for _label, api_key in cfg.auth.api_keys.items():
-            if secrets.compare_digest(token, api_key):
-                authenticated = True
-                break
-
-    if not authenticated:
+    from wled_controller.api.auth import verify_ws_token
+    if not verify_ws_token(token):
         await websocket.close(code=4001, reason="Unauthorized")
         return
 
@@ -737,15 +729,8 @@ async def led_preview_ws(
     token: str = Query(""),
 ):
     """WebSocket for real-time LED strip preview. Sends binary RGB frames. Auth via ?token=<api_key>."""
-    authenticated = False
-    cfg = get_config()
-    if token and cfg.auth.api_keys:
-        for _label, api_key in cfg.auth.api_keys.items():
-            if secrets.compare_digest(token, api_key):
-                authenticated = True
-                break
-
-    if not authenticated:
+    from wled_controller.api.auth import verify_ws_token
+    if not verify_ws_token(token):
         await websocket.close(code=4001, reason="Unauthorized")
         return
 
@@ -777,15 +762,8 @@ async def events_ws(
     token: str = Query(""),
 ):
     """WebSocket for real-time state change events. Auth via ?token=<api_key>."""
-    authenticated = False
-    cfg = get_config()
-    if token and cfg.auth.api_keys:
-        for _label, api_key in cfg.auth.api_keys.items():
-            if secrets.compare_digest(token, api_key):
-                authenticated = True
-                break
-
-    if not authenticated:
+    from wled_controller.api.auth import verify_ws_token
+    if not verify_ws_token(token):
         await websocket.close(code=4001, reason="Unauthorized")
         return