Remove all migration logic, scroll tutorial targets into view, mock URL uses device ID

- Remove legacy migration code: profiles→automations key fallbacks, segments array
  fallback, standby_interval compat, profile_id compat, wled→led type mapping,
  legacy calibration field, audio CSS migration, default template migration,
  loadTargets alias, wled sub-tab mapping
- Scroll tutorial step targets into view when off-screen
- Mock device URL changed from mock://{led_count} to mock://{device_id},
  hide mock URL badge on device cards

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

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

@@ -438,11 +438,6 @@ export async function saveTargetEditor() {
 
 // ===== TARGETS TAB (WLED devices + targets combined) =====
 
-export async function loadTargets() {
-    // Alias for backward compatibility
-    await loadTargetsTab();
-}
-
 export function switchTargetSubTab(tabKey) {
     document.querySelectorAll('.target-sub-tab-btn').forEach(btn =>
         btn.classList.toggle('active', btn.dataset.targetSubTab === tabKey)
@@ -572,9 +567,7 @@ export async function loadTargetsTab() {
         const runningCount = targetsWithState.filter(t => t.state && t.state.processing).length;
         updateTabBadge('targets', runningCount);
 
-        // Backward compat: map stored "wled" sub-tab to "led"
-        let activeSubTab = localStorage.getItem('activeTargetSubTab') || 'led';
-        if (activeSubTab === 'wled') activeSubTab = 'led';
+        const activeSubTab = localStorage.getItem('activeTargetSubTab') || 'led';
 
         const subTabs = [
             { key: 'led', icon: getTargetTypeIcon('led'), titleKey: 'targets.subtab.led', count: ledDevices.length + Object.keys(colorStripSourceMap).length + ledTargets.length },