Split adaptive value source into explicit adaptive_time and adaptive_scene types

Replace single "adaptive" type with adaptive_mode sub-selector by two
distinct source types in the dropdown. Removes the adaptive_mode field
entirely — the source_type itself carries the mode. Clearer UX with
"Adaptive (Time of Day)" and "Adaptive (Scene)" as separate options.

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

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

@@ -112,7 +112,7 @@ import {
 import {
     showValueSourceModal, closeValueSourceModal, saveValueSource,
     editValueSource, deleteValueSource, onValueSourceTypeChange,
-    onAdaptiveModeChange, addSchedulePoint,
+    addSchedulePoint,
 } from './features/value-sources.js';
 
 // Layer 5: calibration
@@ -331,7 +331,6 @@ Object.assign(window, {
     editValueSource,
     deleteValueSource,
     onValueSourceTypeChange,
-    onAdaptiveModeChange,
     addSchedulePoint,
 
     // calibration