#798: Spotify Free UI — enable toggle + source availability

Surfaces the opt-in Spotify Free source so it's usable end-to-end:
- Settings: 'Enable Spotify Free (no credentials)' toggle that saves
  metadata.spotify_free (load + save wired). Clear best-effort/limitations note.
- config-status: adds spotify.metadata_available (configured OR free-available),
  keeping the configured flag = has-credentials so the Connections indicator
  stays honest. Search source picker shows Spotify when metadata_available.
- status payload: adds spotify.metadata_available; the Settings primary-source
  selector now allows picking Spotify when authed OR free-available.

Verified gate composition: OFF by default (no surprise scraping); ON + no auth +
installed -> available & serving; AUTHED -> official always wins (free never
runs); missing package -> gracefully unavailable. JS + integrity + 111 tests green.

web_server.py

@@ -2318,9 +2318,19 @@ def get_status():
                 if t.get('status') in ('downloading', 'searching', 'post_processing', 'queued', 'pending'):
                     active_dl_count += 1
 
+        # Spotify Free: tell the UI whether Spotify metadata is available even
+        # without auth (so the Settings source selector can offer it).
+        spotify_status = dict(metadata_status['spotify'])
+        try:
+            spotify_status['metadata_available'] = bool(
+                spotify_client and spotify_client.is_spotify_metadata_available()
+            )
+        except Exception:
+            spotify_status['metadata_available'] = bool(spotify_status.get('authenticated'))
+
         status_data = {
             'metadata_source': metadata_status['metadata_source'],
-            'spotify': metadata_status['spotify'],
+            'spotify': spotify_status,
             'media_server': _status_cache['media_server'],
             'soulseek': soulseek_data,
             'active_media_server': active_server,
@@ -3665,10 +3675,23 @@ def settings_config_status_endpoint():
     Drives the green/yellow header gradient. No API calls — just config reads.
     """
     try:
-        return jsonify({
+        result = {
             service: {'configured': _is_service_configured(service)}
             for service in SERVICE_CONFIG_REGISTRY
-        })
+        }
+        # Spotify Free: Spotify metadata can be available without credentials
+        # (opt-in no-creds source). Surface that separately so the search source
+        # picker offers Spotify, while `configured` (the Connections indicator)
+        # keeps meaning "has client credentials".
+        if 'spotify' in result:
+            try:
+                meta_avail = bool(spotify_client and spotify_client.is_spotify_metadata_available())
+            except Exception:
+                meta_avail = False
+            result['spotify']['metadata_available'] = (
+                result['spotify']['configured'] or meta_avail
+            )
+        return jsonify(result)
     except Exception as e:
         logger.error(f"config-status error: {e}")
         return jsonify({"error": str(e)}), 500

webui/index.html

@@ -3844,8 +3844,15 @@
                                             <option value="musicbrainz">MusicBrainz</option>
                                         </select>
                                     </div>
+                                    <div class="form-group">
+                                        <label class="checkbox-label">
+                                            <input type="checkbox" id="metadata-spotify-free">
+                                            <span>Enable Spotify Free (no credentials)</span>
+                                        </label>
+                                        <div class="callback-help">Fetch Spotify metadata without API credentials, for when you can't or don't want to connect Spotify. Unofficial &amp; best-effort (it can break if Spotify changes), and it can't search albums by name or access your library — only used when Spotify isn't authenticated.</div>
+                                    </div>
                                     <div class="callback-info">
-                                        <div class="callback-help">Choose the primary source for artist, album, and track metadata. Spotify can only be selected while an active Spotify session exists. Discogs requires a personal token. MusicBrainz is always available but rate-limited to 1 req/sec.</div>
+                                        <div class="callback-help">Choose the primary source for artist, album, and track metadata. Spotify needs an active session — or enable Spotify Free above. Discogs requires a personal token. MusicBrainz is always available but rate-limited to 1 req/sec.</div>
                                     </div>
                                 </div>
 

webui/static/settings.js

@@ -64,7 +64,9 @@ function syncMetadataSourceSelection(source) {
 
 function _isMetadataSourceSelectable(source) {
     if (source === 'spotify') {
-        return _lastStatusPayload?.spotify?.authenticated === true;
+        // Selectable with real auth OR when Spotify Free (no-creds) is available.
+        return _lastStatusPayload?.spotify?.authenticated === true
+            || _lastStatusPayload?.spotify?.metadata_available === true;
     }
     if (source === 'discogs') {
         const token = document.getElementById('discogs-token');
@@ -1045,6 +1047,8 @@ async function loadSettingsData() {
 
         // Populate Metadata source setting
         document.getElementById('metadata-fallback-source').value = settings.metadata?.fallback_source || 'deezer';
+        const spotifyFreeToggle = document.getElementById('metadata-spotify-free');
+        if (spotifyFreeToggle) spotifyFreeToggle.checked = settings.metadata?.spotify_free === true;
 
         // Populate Hydrabase settings
         const hbConfig = settings.hydrabase || {};
@@ -2842,7 +2846,8 @@ async function saveSettings(quiet = false) {
             token: document.getElementById('discogs-token').value,
         },
         metadata: {
-            fallback_source: metadataSource
+            fallback_source: metadataSource,
+            spotify_free: document.getElementById('metadata-spotify-free')?.checked === true
         },
         hydrabase: {
             url: document.getElementById('hydrabase-url').value,

webui/static/shared-helpers.js

@@ -110,6 +110,10 @@ async function fetchSourceConfiguredMap() {
             for (const src of SOURCE_ORDER) {
                 if (_ALWAYS_CONFIGURED_SOURCES.has(src)) {
                     map[src] = true;
+                } else if (src === 'spotify') {
+                    // Spotify Free: available without credentials when the
+                    // opt-in no-creds source is on (metadata_available).
+                    map[src] = !!(data[src] && (data[src].configured || data[src].metadata_available));
                 } else {
                     map[src] = !!(data[src] && data[src].configured);
                 }