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/static/js/app.js

@@ -65,6 +65,9 @@ import {
     addFilterFromSelect, toggleFilterExpand, removeFilter, moveFilter, updateFilterOption,
     renderModalFilterList, updateCaptureDuration,
     cloneStream, cloneCaptureTemplate, clonePPTemplate,
+    showAddCSPTModal, editCSPT, closeCSPTModal, saveCSPT, deleteCSPT, cloneCSPT,
+    csptAddFilterFromSelect, csptToggleFilterExpand, csptRemoveFilter, csptUpdateFilterOption,
+    renderCSPTModalFilterList,
     expandAllStreamSections, collapseAllStreamSections,
 } from './features/streams.js';
 import {
@@ -125,7 +128,7 @@ import {
     onNotificationFilterModeChange,
     notificationAddAppColor, notificationRemoveAppColor,
     testNotification,
-    testColorStrip, closeTestCssSourceModal, applyCssTestSettings, fireCssTestNotification, fireCssTestNotificationLayer,
+    testColorStrip, testCSPT, closeTestCssSourceModal, applyCssTestSettings, fireCssTestNotification, fireCssTestNotificationLayer,
 } from './features/color-strips.js';
 
 // Layer 5: audio sources
@@ -295,6 +298,17 @@ Object.assign(window, {
     cloneStream,
     cloneCaptureTemplate,
     clonePPTemplate,
+    showAddCSPTModal,
+    editCSPT,
+    closeCSPTModal,
+    saveCSPT,
+    deleteCSPT,
+    cloneCSPT,
+    csptAddFilterFromSelect,
+    csptToggleFilterExpand,
+    csptRemoveFilter,
+    csptUpdateFilterOption,
+    renderCSPTModalFilterList,
     showAddAudioTemplateModal,
     editAudioTemplate,
     closeAudioTemplateModal,
@@ -413,7 +427,7 @@ Object.assign(window, {
     onNotificationFilterModeChange,
     notificationAddAppColor, notificationRemoveAppColor,
     testNotification,
-    testColorStrip, closeTestCssSourceModal, applyCssTestSettings, fireCssTestNotification, fireCssTestNotificationLayer,
+    testColorStrip, testCSPT, closeTestCssSourceModal, applyCssTestSettings, fireCssTestNotification, fireCssTestNotificationLayer,
 
     // audio sources
     showAudioSourceModal,