fix(worker): resolve MB to the original edition + loosen duration gate

Root cause of albums re-downloading forever despite completing (Linkin Park "Hybrid
Theory"): the MB resolver read the tracklist from an arbitrary releases[0], often a
later reissue/deluxe. HT resolved to a 2023 13-track reissue (~52 min); a complete
2000 12-track download (~38 min) then failed _download_problem's duration gate
(2267s < 2877s×0.85) and fell through peer after peer, never importing.

- _pick_release: choose the ORIGINAL standard edition (Official, earliest date)
  instead of releases[0], so completeness/duration are judged against the edition
  sources actually deliver.
- _DURATION_MIN_RATIO 0.85 -> 0.65: a source legitimately delivering a shorter
  edition than MB's release shouldn't be rejected; only genuinely truncated/preview
  downloads (a fraction of expected runtime) should be.

Together with the est-time peer ranking, this stops the download→reject→re-download
loop. 334 tests pass.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

worker/tests/test_musicbrainz.py

@@ -1,7 +1,7 @@
 import musicbrainzngs
 import pytest
 
-from lyra_worker._musicbrainz import _best_release_group, _with_retry
+from lyra_worker._musicbrainz import _best_release_group, _pick_release, _with_retry
 
 # Offline unit tests for the pure release-group selection logic. The live resolve()
 # path (network) is covered by test_musicbrainz_live.py.
@@ -68,6 +68,30 @@ def test_prefers_credited_artist_over_same_titled_other_artist_album():
 # --- _with_retry: transient MusicBrainz failures (SSL EOF, 503 rate-limit) ---
 
 
+def test_pick_release_prefers_original_official_over_later_reissue():
+    # Real "Hybrid Theory" bug: MB's arbitrary releases[0] was a 2023 13-track reissue; the 2000
+    # original is what sources deliver, so completeness checks must reference it.
+    releases = [
+        {"id": "reissue", "status": "Official", "date": "2023-06-01"},
+        {"id": "original", "status": "Official", "date": "2000-10-24"},
+        {"id": "deluxe", "status": "Official", "date": "2020-10-09"},
+    ]
+    assert _pick_release(releases)["id"] == "original"
+
+
+def test_pick_release_skips_non_official_and_undated():
+    releases = [
+        {"id": "promo", "status": "Promotion", "date": "1999-01-01"},  # earliest but not official
+        {"id": "undated", "status": "Official", "date": ""},
+        {"id": "official", "status": "Official", "date": "2001-03-03"},
+    ]
+    assert _pick_release(releases)["id"] == "official"
+
+
+def test_pick_release_empty_is_none():
+    assert _pick_release([]) is None
+
+
 def test_retry_returns_value_without_backoff_when_first_call_succeeds():
     sleeps: list[float] = []
     calls = {"n": 0}