Add audio sources as first-class entities, add mapped CSS type, simplify target editor for mapped sources

- Audio sources moved to separate tab with dedicated CRUD API, store, and editor modal
- New "mapped" color strip source type: assigns different CSS sources to distinct LED sub-ranges (zones)
- Mapped stream runtime with per-zone sub-streams, auto-sizing, hot-update support
- Target editor auto-collapses segments UI when mapped CSS is selected
- Delete protection for CSS sources referenced by mapped zones
- Compact header/footer layout

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

server/src/wled_controller/static/js/app.js

@@ -85,7 +85,7 @@ import {
 import {
     loadTargetsTab, loadTargets, switchTargetSubTab,
     showTargetEditor, closeTargetEditorModal, forceCloseTargetEditorModal, saveTargetEditor,
-    addTargetSegment, removeTargetSegment,
+    addTargetSegment, removeTargetSegment, syncSegmentsMappedMode,
     startTargetProcessing, stopTargetProcessing,
     startTargetOverlay, stopTargetOverlay, deleteTarget,
     cloneTarget,
@@ -97,11 +97,18 @@ import {
     onCSSTypeChange, onEffectTypeChange, onAnimationTypeChange, updateEffectPreview,
     colorCycleAddColor, colorCycleRemoveColor,
     compositeAddLayer, compositeRemoveLayer,
+    mappedAddZone, mappedRemoveZone,
     onAudioVizChange,
     applyGradientPreset,
     cloneColorStrip,
 } from './features/color-strips.js';
 
+// Layer 5: audio sources
+import {
+    showAudioSourceModal, closeAudioSourceModal, saveAudioSource,
+    editAudioSource, deleteAudioSource, onAudioSourceTypeChange,
+} from './features/audio-sources.js';
+
 // Layer 5: calibration
 import {
     showCalibration, closeCalibrationModal, forceCloseCalibrationModal, saveCalibration,
@@ -278,6 +285,7 @@ Object.assign(window, {
     saveTargetEditor,
     addTargetSegment,
     removeTargetSegment,
+    syncSegmentsMappedMode,
     startTargetProcessing,
     stopTargetProcessing,
     startTargetOverlay,
@@ -299,10 +307,20 @@ Object.assign(window, {
     colorCycleRemoveColor,
     compositeAddLayer,
     compositeRemoveLayer,
+    mappedAddZone,
+    mappedRemoveZone,
     onAudioVizChange,
     applyGradientPreset,
     cloneColorStrip,
 
+    // audio sources
+    showAudioSourceModal,
+    closeAudioSourceModal,
+    saveAudioSource,
+    editAudioSource,
+    deleteAudioSource,
+    onAudioSourceTypeChange,
+
     // calibration
     showCalibration,
     closeCalibrationModal,