Add Amazon Music as a primary metadata source

Wires AmazonClient into the metadata source registry following the
exact same pattern as DeezerClient. No existing source paths touched.

- Add get_album_metadata / get_artist_info / get_artist_albums_list
  aliases to AmazonClient (mirrors DeezerClient interface aliases)
- Register amazon in METADATA_SOURCE_PRIORITY and METADATA_SOURCE_LABELS
- Add _get_amazon_factory() + get_amazon_client() to registry.py
- Add amazon branch to get_client_for_source(); thread amazon_client_factory
  kwarg through get_primary_client() and get_primary_source_status()
- Re-export get_amazon_client from the core.metadata_service shim
- Add Amazon Music option to Settings metadata source dropdown
- 3530 tests pass

core/amazon_client.py

@@ -511,6 +511,11 @@ class AmazonClient:
         """Not available from Amazon Music — returns None for compatibility."""
         return None
 
+    # ==================== Interface Aliases (match DeezerClient method names) ====================
+    get_album_metadata = get_album
+    get_artist_info = get_artist
+    get_artist_albums_list = get_artist_albums
+
     # ------------------------------------------------------------------
     # Private helpers
     # ------------------------------------------------------------------

core/metadata/registry.py

@@ -18,13 +18,14 @@ logger = get_logger("metadata.registry")
 
 MetadataClientFactory = Callable[[], Any]
 
-METADATA_SOURCE_PRIORITY = ("deezer", "itunes", "spotify", "discogs", "hydrabase")
+METADATA_SOURCE_PRIORITY = ("deezer", "itunes", "spotify", "discogs", "hydrabase", "amazon")
 METADATA_SOURCE_LABELS = {
     "spotify": "Spotify",
     "itunes": "iTunes",
     "deezer": "Deezer",
     "discogs": "Discogs",
     "hydrabase": "Hydrabase",
+    "amazon": "Amazon Music",
 }
 
 _UNSET = object()
@@ -140,6 +141,14 @@ def _get_discogs_factory(client_factory: Optional[MetadataClientFactory]) -> Met
     return DiscogsClient
 
 
+def _get_amazon_factory(client_factory: Optional[MetadataClientFactory]) -> MetadataClientFactory:
+    if client_factory is not None:
+        return client_factory
+    from core.amazon_client import AmazonClient
+
+    return AmazonClient
+
+
 def get_spotify_client(client_factory: Optional[MetadataClientFactory] = None):
     """Get shared Spotify client.
 
@@ -260,6 +269,18 @@ def get_discogs_client(
         return client
 
 
+def get_amazon_client(client_factory: Optional[MetadataClientFactory] = None):
+    """Get cached Amazon Music client."""
+    cache_key = "amazon"
+    factory = _get_amazon_factory(client_factory)
+    with _client_cache_lock:
+        client = _client_cache.get(cache_key)
+        if client is None:
+            client = factory()
+            _client_cache[cache_key] = client
+        return client
+
+
 def is_hydrabase_enabled() -> bool:
     """Return True when Hydrabase is connected and app-enabled."""
     try:
@@ -331,6 +352,7 @@ def get_primary_client(
     itunes_client_factory: Optional[MetadataClientFactory] = None,
     deezer_client_factory: Optional[MetadataClientFactory] = None,
     discogs_client_factory: Optional[MetadataClientFactory] = None,
+    amazon_client_factory: Optional[MetadataClientFactory] = None,
 ):
     """Return client for configured primary source."""
     return get_client_for_source(
@@ -339,6 +361,7 @@ def get_primary_client(
         itunes_client_factory=itunes_client_factory,
         deezer_client_factory=deezer_client_factory,
         discogs_client_factory=discogs_client_factory,
+        amazon_client_factory=amazon_client_factory,
     )
 
 
@@ -348,6 +371,7 @@ def get_primary_source_status(
     itunes_client_factory: Optional[MetadataClientFactory] = None,
     deezer_client_factory: Optional[MetadataClientFactory] = None,
     discogs_client_factory: Optional[MetadataClientFactory] = None,
+    amazon_client_factory: Optional[MetadataClientFactory] = None,
 ) -> Dict[str, Any]:
     """Return a generic status snapshot for the active primary metadata source."""
     source = _get_config_value("metadata.fallback_source", "deezer") or "deezer"
@@ -361,6 +385,7 @@ def get_primary_source_status(
             itunes_client_factory=itunes_client_factory,
             deezer_client_factory=deezer_client_factory,
             discogs_client_factory=discogs_client_factory,
+            amazon_client_factory=amazon_client_factory,
         )
         if source == "spotify":
             connected = bool(client and client.is_spotify_authenticated())
@@ -387,6 +412,7 @@ def get_client_for_source(
     itunes_client_factory: Optional[MetadataClientFactory] = None,
     deezer_client_factory: Optional[MetadataClientFactory] = None,
     discogs_client_factory: Optional[MetadataClientFactory] = None,
+    amazon_client_factory: Optional[MetadataClientFactory] = None,
 ):
     """Return exact client for a source, or None if unavailable."""
     if source == "spotify":
@@ -410,4 +436,7 @@ def get_client_for_source(
     if source == "itunes":
         return get_itunes_client(client_factory=itunes_client_factory)
 
+    if source == "amazon":
+        return get_amazon_client(client_factory=amazon_client_factory)
+
     return None

core/metadata_service.py

@@ -42,6 +42,7 @@ from core.metadata.registry import (
     clear_cached_metadata_client,
     clear_cached_metadata_clients,
     clear_cached_profile_spotify_client,
+    get_amazon_client,
     get_client_for_source,
     get_deezer_client,
     get_discogs_client,
@@ -75,6 +76,7 @@ except Exception:  # pragma: no cover - optional dependency fallback
 
 __all__ = [
     "METADATA_SOURCE_PRIORITY",
+    "get_amazon_client",
     "MetadataCache",
     "MetadataLookupOptions",
     "MetadataProvider",

webui/index.html

@@ -3632,10 +3632,11 @@
                                             <option value="itunes">iTunes / Apple Music</option>
                                             <option value="deezer">Deezer</option>
                                             <option value="discogs">Discogs</option>
+                                            <option value="amazon">Amazon Music</option>
                                         </select>
                                     </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.</div>
+                                        <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. Amazon Music uses the T2Tunes proxy — no account needed.</div>
                                     </div>
                                 </div>
 

webui/static/helper.js

@@ -3415,6 +3415,7 @@ function closeHelperSearch() {
 const WHATS_NEW = {
     '2.5.3': [
         { unreleased: true },
+        { title: 'Amazon Music Metadata Source', desc: 'Amazon Music is now a selectable primary metadata source alongside Spotify, iTunes, Deezer, and Discogs. backed by the same T2Tunes proxy as the download source — no account needed. covers track search, album lookup with cover art, and artist discography. select it under Settings → Connections → Metadata Source.', page: 'settings' },
         { title: 'Amazon Music Download Source', desc: 'new download source backed by T2Tunes proxy. searches the Amazon Music catalog, downloads 24-bit/48kHz FLAC (or Opus 320kbps / Dolby Atmos EAC3 fallback). codec waterfall mirrors Tidal/Qobuz — best quality first, auto-fallback. selectable as a standalone or hybrid source from Settings.', page: 'settings' },
     ],
     '2.5.2': [