feat(lucky-mix): instant mix from your preferences

Lucky Mix targets ~50 tracks in one run: pick seeds from your most-played artists/albums and 4+ rated songs, add similar tracks, then fill the mix with random library picks, skipping anything you rated 1–2.
On start it trims the old “upcoming” tail so the queue does not show stale next tracks, starts playback on the first viable seed, routes to Now Playing, and can emit structured steps to the backend debug log.

src/pages/LuckyMix.tsx

@@ -0,0 +1,17 @@
+import { useEffect, useRef } from 'react';
+import { useNavigate } from 'react-router-dom';
+import { buildAndPlayLuckyMix } from '../utils/luckyMix';
+
+export default function LuckyMixPage() {
+  const navigate = useNavigate();
+  const startedRef = useRef(false);
+
+  useEffect(() => {
+    if (startedRef.current) return;
+    startedRef.current = true;
+    void buildAndPlayLuckyMix();
+    navigate('/now-playing', { replace: true });
+  }, [navigate]);
+
+  return null;
+}

src/pages/RandomLanding.tsx

@@ -1,7 +1,8 @@
 import React from 'react';
 import { useNavigate } from 'react-router-dom';
 import { useTranslation } from 'react-i18next';
-import { Shuffle, Dices } from 'lucide-react';
+import { Shuffle, Dices, Sparkles } from 'lucide-react';
+import { useAuthStore } from '../store/authStore';
 
 interface MixCard {
   icon: React.ElementType;
@@ -28,11 +29,26 @@ const CARDS: MixCard[] = [
 export default function RandomLanding() {
   const { t } = useTranslation();
   const navigate = useNavigate();
+  const activeServerId = useAuthStore(s => s.activeServerId);
+  const showLuckyMixMenu = useAuthStore(s => s.showLuckyMixMenu);
+  const audiomuseByServer = useAuthStore(s => s.audiomuseNavidromeByServer);
+  const luckyMixAvailable = showLuckyMixMenu && Boolean(activeServerId && audiomuseByServer[activeServerId]);
+  const cards = luckyMixAvailable
+    ? [
+        ...CARDS,
+        {
+          icon: Sparkles,
+          labelKey: 'randomLanding.mixByLucky',
+          descKey: 'randomLanding.mixByLuckyDesc',
+          to: '/lucky-mix',
+        },
+      ]
+    : CARDS;
 
   return (
     <div className="random-landing">
       <div className="random-landing-grid">
-        {CARDS.map(({ icon: Icon, labelKey, descKey, to }) => (
+        {cards.map(({ icon: Icon, labelKey, descKey, to }) => (
           <button
             key={to}
             className="mix-pick-card"

src/pages/Settings.tsx

@@ -2658,6 +2658,25 @@ export default function Settings() {
 
               <div className="divider" style={{ margin: '1rem 0' }} />
 
+              <div className="settings-toggle-row" style={{ marginBottom: '1rem' }}>
+                <div>
+                  <div style={{ fontWeight: 500 }}>{t('settings.luckyMixMenuTitle')}</div>
+                  <div style={{ fontSize: 12, color: 'var(--text-muted)' }}>
+                    {t('settings.luckyMixMenuDesc')}
+                  </div>
+                </div>
+                <label className="toggle-switch" aria-label={t('settings.luckyMixMenuTitle')}>
+                  <input
+                    type="checkbox"
+                    checked={auth.showLuckyMixMenu}
+                    onChange={e => auth.setShowLuckyMixMenu(e.target.checked)}
+                  />
+                  <span className="toggle-track" />
+                </label>
+              </div>
+
+              <div className="divider" style={{ margin: '1rem 0' }} />
+
               <div style={{ fontSize: 13, fontWeight: 500, marginBottom: '0.5rem', color: 'var(--text-muted)' }}>{t('settings.randomMixHardcodedTitle')}</div>
               <div style={{ display: 'flex', flexWrap: 'wrap', gap: '0.4rem' }}>
                 {AUDIOBOOK_GENRES_DISPLAY.map(genre => (
@@ -4394,11 +4413,16 @@ function SidebarCustomizer() {
   itemsRef.current = items;
   const randomNavMode = useAuthStore(s => s.randomNavMode);
   const setRandomNavMode = useAuthStore(s => s.setRandomNavMode);
+  const activeServerId = useAuthStore(s => s.activeServerId);
+  const audiomuseByServer = useAuthStore(s => s.audiomuseNavidromeByServer);
+  const showLuckyMixMenu = useAuthStore(s => s.showLuckyMixMenu);
+  const luckyMixAvailable = randomNavMode === 'separate' && showLuckyMixMenu && Boolean(activeServerId && audiomuseByServer[activeServerId]);
 
   const libraryItems = items.filter(cfg => {
     if (!ALL_NAV_ITEMS[cfg.id] || ALL_NAV_ITEMS[cfg.id].section !== 'library') return false;
-    if (randomNavMode === 'hub' && (cfg.id === 'randomMix' || cfg.id === 'randomAlbums')) return false;
+    if (randomNavMode === 'hub' && (cfg.id === 'randomMix' || cfg.id === 'randomAlbums' || cfg.id === 'luckyMix')) return false;
     if (randomNavMode === 'separate' && cfg.id === 'randomPicker') return false;
+    if (cfg.id === 'luckyMix' && !luckyMixAvailable) return false;
     return true;
   });
   const systemItems  = items.filter(cfg => ALL_NAV_ITEMS[cfg.id]?.section === 'system');