ingest: retry transient HTTP connection errors

Give the outgoing HTTP clients (Navidrome, MusicBrainz, ListenBrainz) a
transport-level retry budget (RADIEO_HTTP_RETRIES, default 2) so a brief
connection blip on a remote endpoint no longer drops a fetch or a lookup.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

ingest/radieo/subsonic.py

@@ -11,6 +11,8 @@ from pathlib import Path
 
 import httpx
 
+from . import config
+
 log = logging.getLogger("radieo.subsonic")
 
 # Advertised API version and client name.
@@ -43,7 +45,11 @@ class SubsonicClient:
         self._base = base_url.rstrip("/")
         self._user = user
         self._password = password
-        self._http = httpx.Client(timeout=30.0, follow_redirects=True)
+        self._http = httpx.Client(
+            timeout=30.0,
+            follow_redirects=True,
+            transport=httpx.HTTPTransport(retries=config.HTTP_RETRIES),
+        )
 
     def _auth_params(self) -> dict[str, str]:
         salt = secrets.token_hex(8)