fix(r5): address the second /code-review high round — 7 findings

- the volume keys no longer defer to a scrollable card while in fullscreen
  (mirrored into a ref: the keydown handler is bound once and state would be stale)
- the debounced volume flush writes straight to storage; persisting inside a
  setState updater is not guaranteed to run for an unmounting component
- the HLS sweep also matches the original {key}_{start} directory naming, which
  is what the oldest leftovers on disk actually use
- run_rss_poll returns {new, failed} so an egress outage stops rendering as
  "ok — 0" in the scheduler card and the audit log; /api/sync/rss reports it too
- drop the unused poll_rss_channel (it silently gained a new exception)
- _Breaker.run is generic, so a call site keeps its item-id type
- test helper instead of the generator-throw idiom

backend/app/plex/stream.py

@@ -34,11 +34,13 @@ log = logging.getLogger("siftlode.plex")
 _HLS_ROOT = Path(settings.plex_hls_dir) if settings.plex_hls_dir else Path(settings.download_root) / ".plex-hls"
 _SEG_SECONDS = 6
 _SESSION_IDLE_S = 600  # reap a session with no access for this long
-# A session directory is named `{rating_key}_{int(start_s)}_{tag}_{aoff:+.2f}` (see start_session).
-# `sweep_orphans` deletes ONLY names matching this shape: `_HLS_ROOT` is admin-configurable
+# A session directory is named `{rating_key}_{int(start_s)}_{tag}_{aoff:+.2f}` (see start_session);
+# before multi-audio it was just `{rating_key}_{int(start_s)}`, so the tail is OPTIONAL here — the
+# oldest leftovers on disk carry the old shape and are exactly what the sweep exists to remove.
+# `sweep_orphans` deletes ONLY names matching this: `_HLS_ROOT` is admin-configurable
 # (PLEX_HLS_DIR), so it may legitimately point at a shared scratch path we do not own — a blanket
 # "delete every directory under the root" would take the neighbours with it.
-_SESSION_DIR_RE = re.compile(r"^.+_\d+_[^_]+_[+-]\d+\.\d{2}$")
+_SESSION_DIR_RE = re.compile(r"^.+_\d+(_[^_]+_[+-]\d+\.\d{2})?$")
 
 _lock = threading.Lock()
 _sessions: dict[str, "HlsSession"] = {}

backend/app/routes/sync.py

@@ -52,8 +52,10 @@ def sync_subscriptions(
 def sync_rss(
     user: User = Depends(require_human), db: Session = Depends(get_db)
 ) -> dict:
-    new = run_rss_poll(db, _user_channels(db, user))
-    return {"new_videos": new}
+    result = run_rss_poll(db, _user_channels(db, user))
+    # `failed` = feeds that could not be read at all (see run_rss_poll); surfaced so a manual poll
+    # reports an outage instead of an innocent-looking "0 new".
+    return {"new_videos": result["new"], "failed_feeds": result["failed"]}
 
 
 @router.post("/backfill")

backend/app/sync/playlists.py

@@ -9,6 +9,7 @@ import hashlib
 import logging
 from collections.abc import Callable
 from datetime import datetime, timezone
+from typing import TypeVar
 
 from sqlalchemy import delete, select
 from sqlalchemy.orm import Session
@@ -272,8 +273,15 @@ def plan_push(db: Session, user: User, pl: Playlist, *, live=None) -> dict:
 _MAX_CONSECUTIVE_FAILURES = 5
 
 
+class _Failed:
+    """Type of the `FAILED` sentinel, so `run()` can stay generic in the op's return type: a call
+    site gets back `str | _Failed` (not a bare `object`) and keeps its item id typed."""
+
+
 #: Returned by `_Breaker.run` when the write did not happen (refused or failed).
-FAILED = object()
+FAILED = _Failed()
+
+T = TypeVar("T")
 
 
 class _Breaker:
@@ -305,7 +313,7 @@ class _Breaker:
                 self.limit,
             )
 
-    def run(self, op: Callable[[], object], on_fail: Callable[[], None]) -> object:
+    def run(self, op: Callable[[], T], on_fail: Callable[[], None]) -> T | _Failed:
         """Attempt one YouTube write. Returns the op's result, or `FAILED` when the breaker is
         already tripped (op not called) or the op raised YouTubeError. `on_fail` records the item
         in the caller's failure list either way."""
@@ -387,7 +395,7 @@ def push_playlist(db: Session, user: User, pl: Playlist, *, live=None) -> dict:
                     lambda v=vid: yt.add_playlist_item(pl.yt_playlist_id, v),
                     lambda v=vid: failures.append(v),
                 )
-                if item_id is not FAILED:
+                if not isinstance(item_id, _Failed):
                     item_id_by_vid[vid] = item_id
                     inserted += 1
         # Reorder to match `desired` via insertion-sort moves over a local model.

backend/app/sync/runner.py

@@ -48,7 +48,11 @@ def get_service_user(db: Session) -> User | None:
     return users[0] if users else None
 
 
-def run_rss_poll(db: Session, channels: list[Channel] | None = None) -> int:
+def run_rss_poll(db: Session, channels: list[Channel] | None = None) -> dict:
+    """Poll every channel's free RSS feed. Returns `{"new": inserted, "failed": unreadable_feeds}`
+    — the failure count is part of the RESULT, not just a log line, so the scheduler card and the
+    audit summary can tell "no new uploads" apart from "every feed was unreachable" (an egress
+    outage otherwise renders identically to a quiet hour)."""
     if channels is None:
         channels = db.execute(select(Channel)).scalars().all()
     total = len(channels)
@@ -89,7 +93,7 @@ def run_rss_poll(db: Session, channels: list[Channel] | None = None) -> int:
             progress.report(done, total, "rss_poll")
     if failed:
         log.warning("RSS poll: %d/%d channel feeds could not be read", failed, total)
-    return new
+    return {"new": new, "failed": failed}
 
 
 def run_enrich(db: Session, max_batches: int = 200, floor: int = 200) -> int:

backend/app/sync/videos.py

@@ -14,7 +14,6 @@ from app import progress, sysconfig
 from app.models import LIVE_OR_UPCOMING, Channel, Video
 from app.titles import normalize_title
 from app.youtube.client import YouTubeClient, best_thumbnail
-from app.youtube.rss import fetch_channel_feed
 from app.youtube.shorts import make_client, probe_is_short
 
 _DURATION_RE = re.compile(
@@ -84,10 +83,6 @@ def apply_rss_feed(db: Session, channel: Channel, entries: list[dict]) -> int:
     return inserted
 
 
-def poll_rss_channel(db: Session, channel: Channel) -> int:
-    return apply_rss_feed(db, channel, fetch_channel_feed(channel.id))
-
-
 # --- Backfill (uploads playlist; costs quota) ---
 def _stub_from_playlist_item(item: dict, channel_id: str) -> dict | None:
     content = item.get("contentDetails", {})

backend/tests/test_sync_guards.py

@@ -51,6 +51,11 @@ class TestBreaker:
         assert not b.open()
 
 
+def _quota_dead():
+    """A write op that fails the way a quota-exhausted / scope-revoked account fails."""
+    raise YouTubeError("quota exceeded")
+
+
 class TestBreakerRun:
     def test_returns_the_ops_result_and_leaves_failures_alone(self):
         b, failed = _Breaker(), []
@@ -59,22 +64,25 @@ class TestBreakerRun:
 
     def test_a_youtube_error_records_the_failure_and_counts_towards_the_trip(self):
         b, failed = _Breaker(limit=2), []
-        assert b.run(lambda: (_ for _ in ()).throw(YouTubeError("quota")), lambda: failed.append("v1")) is FAILED
+        assert b.run(_quota_dead, lambda: failed.append("v1")) is FAILED
         assert failed == ["v1"] and b.open()
-        b.run(lambda: (_ for _ in ()).throw(YouTubeError("quota")), lambda: failed.append("v2"))
+        b.run(_quota_dead, lambda: failed.append("v2"))
         assert not b.open()
 
     def test_a_tripped_breaker_never_calls_the_op(self):
         b, failed, calls = _Breaker(limit=1), [], []
-        b.run(lambda: (_ for _ in ()).throw(YouTubeError("quota")), lambda: failed.append("v1"))
+        b.run(_quota_dead, lambda: failed.append("v1"))
         assert b.run(lambda: calls.append("called"), lambda: failed.append("v2")) is FAILED
         assert calls == []  # the whole point: no more quota spent
         assert failed == ["v1", "v2"]  # …but the item is still reported
 
     def test_other_exceptions_are_not_swallowed(self):
         # Only YouTubeError is a "write failed" signal; a bug must still surface.
+        def boom():
+            raise ValueError("bug")
+
         with pytest.raises(ValueError):
-            _Breaker().run(lambda: (_ for _ in ()).throw(ValueError("bug")), lambda: None)
+            _Breaker().run(boom, lambda: None)
 
 
 class TestRssErrorVsEmpty: