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/canonicalizer.py

@@ -32,6 +32,7 @@ class Canonicalizer:
             timeout=httpx.Timeout(connect=10.0, read=30.0, write=10.0, pool=10.0),
             headers={"User-Agent": config.USER_AGENT},
             follow_redirects=True,
+            transport=httpx.HTTPTransport(retries=config.HTTP_RETRIES),
         )
         self._rate_lock = threading.Lock()
         self._last_call = 0.0

ingest/radieo/config.py

@@ -18,6 +18,10 @@ STATE_DB = STATE_DIR / "radieo.db"
 HTTP_HOST = os.environ.get("RADIEO_HTTP_HOST", "0.0.0.0")
 HTTP_PORT = int(os.environ.get("RADIEO_HTTP_PORT", "8080"))
 
+# Transport-level retries for transient connection errors on outgoing HTTP
+# (Navidrome, MusicBrainz, ListenBrainz). Applies to connect failures only.
+HTTP_RETRIES = int(os.environ.get("RADIEO_HTTP_RETRIES", "2"))
+
 # --- Prefetching / retention ---
 # How many downloaded tracks to keep ready ahead of playback.
 PREFETCH = int(os.environ.get("RADIEO_PREFETCH", "3"))

ingest/radieo/providers/listenbrainz.py

@@ -66,6 +66,7 @@ class ListenBrainzProvider:
             timeout=httpx.Timeout(connect=10.0, read=30.0, write=10.0, pool=10.0),
             headers={"User-Agent": config.USER_AGENT},
             follow_redirects=True,
+            transport=httpx.HTTPTransport(retries=config.HTTP_RETRIES),
         )
         self._recs: list[dict] = []
         self._loaded_at = 0.0

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)