Add interactive getting-started tutorial for first-time users

Auto-starts on first visit with a 9-step walkthrough covering header,
tabs, settings, search, theme, and language controls. Stores completion
in localStorage; restart via ? button in the header. Includes en/ru/zh
translations for all tour steps.

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

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

@@ -19,6 +19,20 @@ const calibrationTutorialSteps = [
     { selector: '#cal-skip-end', textKey: 'calibration.tip.skip_leds_end', position: 'top' }
 ];
 
+const TOUR_KEY = 'tour_completed';
+
+const gettingStartedSteps = [
+    { selector: 'header .header-title', textKey: 'tour.welcome', position: 'bottom' },
+    { selector: '#tab-btn-dashboard', textKey: 'tour.dashboard', position: 'bottom' },
+    { selector: '#tab-btn-targets', textKey: 'tour.targets', position: 'bottom' },
+    { selector: '#tab-btn-streams', textKey: 'tour.sources', position: 'bottom' },
+    { selector: '#tab-btn-profiles', textKey: 'tour.profiles', position: 'bottom' },
+    { selector: '[onclick*="openSettingsModal"]', textKey: 'tour.settings', position: 'bottom' },
+    { selector: '[onclick*="openCommandPalette"]', textKey: 'tour.search', position: 'bottom' },
+    { selector: '.theme-toggle', textKey: 'tour.theme', position: 'bottom' },
+    { selector: '#locale-select', textKey: 'tour.language', position: 'bottom' }
+];
+
 const deviceTutorialSteps = [
     { selector: '.card-subtitle', textKey: 'device.tip.metadata', position: 'bottom' },
     { selector: '.brightness-control', textKey: 'device.tip.brightness', position: 'bottom' },
@@ -40,7 +54,8 @@ export function startTutorial(config) {
         mode: config.mode,
         step: 0,
         resolveTarget: config.resolveTarget,
-        container: config.container
+        container: config.container,
+        onClose: config.onClose || null
     });
 
     overlay.classList.add('active');
@@ -86,8 +101,20 @@ export function startDeviceTutorial(deviceId) {
     });
 }
 
+export function startGettingStartedTutorial() {
+    startTutorial({
+        steps: gettingStartedSteps,
+        overlayId: 'getting-started-overlay',
+        mode: 'fixed',
+        container: null,
+        resolveTarget: (step) => document.querySelector(step.selector) || null,
+        onClose: () => localStorage.setItem(TOUR_KEY, '1')
+    });
+}
+
 export function closeTutorial() {
     if (!activeTutorial) return;
+    const onClose = activeTutorial.onClose;
     activeTutorial.overlay.classList.remove('active');
     document.querySelectorAll('.tutorial-target').forEach(el => {
         el.classList.remove('tutorial-target');
@@ -95,6 +122,7 @@ export function closeTutorial() {
     });
     document.removeEventListener('keydown', handleTutorialKey);
     setActiveTutorial(null);
+    if (onClose) onClose();
 }
 
 export function tutorialNext() {