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/tutorials.js

@@ -249,6 +249,12 @@ function showTutorialStep(index, direction = 1) {
     target.classList.add('tutorial-target');
     if (isFixed) target.style.zIndex = '10001';
 
+    // Scroll target into view if off-screen
+    const preRect = target.getBoundingClientRect();
+    if (preRect.bottom > window.innerHeight || preRect.top < 0) {
+        target.scrollIntoView({ behavior: 'instant', block: 'center' });
+    }
+
     const targetRect = target.getBoundingClientRect();
     const pad = 6;
     let x, y, w, h;