Simplify scenes to capture only target state, add target selector

- Remove DeviceBrightnessSnapshot and AutomationSnapshot from scene data model
- Simplify capture_current_snapshot and apply_scene_state to targets only
- Remove device/automation dependencies from scene preset API routes
- Add target selector (combobox + add/remove) to scene capture modal
- Fix stale profiles reference bug in scene_preset_store recapture
- Update automation engine call sites for simplified scene functions
- Sync scene presets cache between automations and scene-presets modules

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

server/src/wled_controller/static/js/features/automations.js

@@ -10,7 +10,7 @@ import { Modal } from '../core/modal.js';
 import { CardSection } from '../core/card-sections.js';
 import { updateTabBadge } from './tabs.js';
 import { ICON_SETTINGS, ICON_START, ICON_PAUSE, ICON_CLOCK, ICON_AUTOMATION, ICON_HELP, ICON_OK, ICON_TIMER, ICON_MONITOR, ICON_RADIO, ICON_SCENE } from '../core/icons.js';
-import { csScenes, createSceneCard } from './scene-presets.js';
+import { csScenes, createSceneCard, updatePresetsCache } from './scene-presets.js';
 
 // ===== Scene presets cache (shared by both selectors) =====
 let _scenesCache = [];
@@ -62,6 +62,7 @@ export async function loadAutomations() {
         const data = await automationsResp.json();
         const scenesData = scenesResp.ok ? await scenesResp.json() : { presets: [] };
         _scenesCache = scenesData.presets || [];
+        updatePresetsCache(_scenesCache);
 
         // Build scene name map for card rendering
         const sceneMap = new Map(_scenesCache.map(s => [s.id, s]));
@@ -208,6 +209,7 @@ export async function openAutomationEditor(automationId) {
         if (resp.ok) {
             const data = await resp.json();
             _scenesCache = data.presets || [];
+            updatePresetsCache(_scenesCache);
         }
     } catch { /* use cached */ }