fix: remove Spotify credential requirement — no API keys needed

spotdl (SpotAPI) works without developer credentials. Remove the
health-check warning, credential error UI, and Client Credentials
fallback that were blocking the importer.

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

backend/novasonic-server.js

@@ -224,29 +224,7 @@ async function fetchSpotifyToken() {
     _spSecretCache = null; // force secret re-extraction next time
   }
 
-  // Approach 2: Client Credentials fallback (requires SPOTIFY_CLIENT_ID/SECRET in env)
-  if (!CONFIG.spotifyClientId || !CONFIG.spotifyClientSecret) {
-    throw new Error(
-      'Spotify-Token nicht abrufbar (TOTP gescheitert). ' +
-      'SPOTIFY_CLIENT_ID und SPOTIFY_CLIENT_SECRET setzen als Fallback.'
-    );
-  }
-  const basic = Buffer.from(`${CONFIG.spotifyClientId}:${CONFIG.spotifyClientSecret}`).toString('base64');
-  const r = await _fetchTimeout('https://accounts.spotify.com/api/token', {
-    method: 'POST',
-    headers: { 'Authorization': `Basic ${basic}`, 'Content-Type': 'application/x-www-form-urlencoded' },
-    body: 'grant_type=client_credentials',
-  });
-  if (!r.ok) {
-    const errBody = await r.text().catch(() => '');
-    throw new Error(`Spotify-Token-Fehler (${r.status}): ${errBody.slice(0, 200)}`);
-  }
-  const d = await r.json();
-  if (!d.access_token) throw new Error('Kein access_token von Spotify erhalten');
-  _spTokenCache  = d.access_token;
-  _spTokenExpiry = Date.now() + (d.expires_in * 1000) - 30000;
-  console.log('[spotify] token ok (Client Credentials)');
-  return _spTokenCache;
+  throw new Error('Spotify-Token nicht abrufbar (TOTP gescheitert)');
 }
 
 async function _spApi(path, token) {
@@ -370,9 +348,7 @@ app.get('/api/health', (req, res) => {
     squidQuality: CONFIG.squidQuality,
     activeJobs: activeDownloads,
     queueLength: downloadQueue.length,
-    spotify: {
-      configured: !!(CONFIG.spotifyClientId && CONFIG.spotifyClientSecret),
-    },
+    spotify: { configured: true },
   });
 });
 

src/spotify.js

@@ -6,32 +6,13 @@ import { makeGlobalTrackItem } from './components.js';
 import { openDlModal } from './ui.js';
 
 // ─── SPOTIFY IMPORTER PAGE ───
-export async function loadSpotifyImporter() {
+export function loadSpotifyImporter() {
   if (!document.getElementById('spotify-link-input')?.value) {
     const hint    = document.getElementById('spotify-importer-hint');
     const preview = document.getElementById('spotify-preview');
     if (hint)    hint.style.display    = '';
     if (preview) preview.style.display = 'none';
   }
-
-  if (S.cfg.backendUrl) {
-    try {
-      const h = await fetch(`${S.cfg.backendUrl}/api/health`, { signal: AbortSignal.timeout(5000) }).then(r => r.json());
-      if (!h.spotify?.configured) {
-        const input = document.getElementById('spotify-link-input');
-        if (input) {
-          input.disabled = true;
-          input.placeholder = 'Spotify-Importer nicht konfiguriert (Server-Setup erforderlich)';
-        }
-        const hint = document.getElementById('spotify-importer-hint');
-        if (hint) hint.innerHTML += `
-          <div style="margin-top:16px;padding:12px;background:var(--surface);border-radius:10px;border-left:3px solid #1DB954;font-size:13px;color:var(--text2)">
-            ⚠ Server-Admin muss <code>SPOTIFY_CLIENT_ID</code> und <code>SPOTIFY_CLIENT_SECRET</code> setzen.
-            Kostenlos unter <a href="https://developer.spotify.com/dashboard" target="_blank" style="color:#1DB954">developer.spotify.com/dashboard</a>.
-          </div>`;
-      }
-    } catch { /* health check failed — leave UI as-is */ }
-  }
 }
 
 export function clearSpotifyPreview() {
@@ -108,24 +89,6 @@ export async function resolveSpotifyLink() {
       </div>`;
       return;
     }
-    if (e.message.includes('SPOTIFY_CLIENT_ID') ||
-        e.message.includes('Credentials fehlen') ||
-        e.message.includes('Spotify-Token-Fehler')) {
-      inner.innerHTML = `<div style="color:var(--text);padding:16px;background:var(--surface);border-radius:10px;border-left:3px solid #1DB954">
-        <div style="font-weight:600;margin-bottom:8px">Spotify-Importer nicht konfiguriert</div>
-        <div style="font-size:13px;line-height:1.5">
-          Der Server-Admin muss einmalig Spotify-Credentials hinterlegen.<br><br>
-          Schritte:<br>
-          1. <a href="https://developer.spotify.com/dashboard" target="_blank" style="color:#1DB954">developer.spotify.com/dashboard</a> öffnen<br>
-          2. "Create app" — Name beliebig, Redirect URI: <code>http://localhost</code><br>
-          3. Client ID + Secret als Environment-Variablen setzen:<br>
-          &nbsp;&nbsp;<code>SPOTIFY_CLIENT_ID=...</code><br>
-          &nbsp;&nbsp;<code>SPOTIFY_CLIENT_SECRET=...</code><br>
-          4. Backend neu starten
-        </div>
-      </div>`;
-      return;
-    }
     inner.innerHTML = `<div style="color:var(--danger);padding:16px;background:var(--surface);border-radius:10px">${esc(e.message)}</div>`;
   }
 }