fix: reliable YouTube tagging, loud Lidarr failures, deno runtime, repair recovery

Root cause of bad album/title tags: yt-dlp's --parse-metadata reads a
single-word FROM (matching field_to_template's ^[a-zA-Z_]+$) as a *field
name*, so literal one-word titles/albums like "Cochise" became "NA". Inject
literals via seed-then-replace into meta_<tag> instead (--parse-metadata to
create the field, --replace-in-metadata with literal args to set it), which
is immune to template parsing and also creates tags the source lacks.

- yt_download: literal-safe meta_artist/title/album; hit album no longer
  clobbered by the Unknown-Album default; artist tag now created when missing.
- lidarr_search: connection/timeout errors surface via err() ("Lidarr
  unreachable … falling back to YouTube") instead of silent dbg(), so the
  YouTube fallback isn't mistaken for "no Lidarr match".
- Dockerfile: install deno (arch-aware) — the JS runtime yt-dlp needs for
  YouTube; without it: "No supported JavaScript runtime" / HTTP 403.
- repair: treat NA/Unknown placeholders as bogus and overwrite title/artist
  from source (was fill-missing-only); normalise literal "NA" album to
  "Unknown Album"; rename bogus "NA [<id>]" filenames to the recovered title.
- README updated; .gitignore excludes server/log.txt.

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

tests/test_repair.py

@@ -260,3 +260,79 @@ def test_retag_library_walks_source_files(tmp_path, monkeypatch):
     scanned, changed = mf.retag_library_from_path(str(root), dry_run=False)
     assert (scanned, changed) == (1, 1)
     assert visited == ["Daft Punk"]
+
+
+# ---- bogus-tag recovery (old-code NA / Unknown breakage) ----
+def test_is_bogus():
+    for v in ("", "NA", "na", "N/A", "Unknown", "Unknown Album", "unknown artist", "  NA  "):
+        assert mf._is_bogus(v) is True, v
+    for v in ("Cochise", "Solid", "Brother Stoon", "Discovery"):
+        assert mf._is_bogus(v) is False, v
+
+
+def test_repair_file_overwrites_bogus_title(monkeypatch):
+    monkeypatch.setattr(mf, "run_yt_dlp_get_metadata",
+                        lambda url, *a: {"artist": "Audioslave", "title": "Cochise",
+                                         "album": "Audioslave", "release_year": 2002})
+    audio = _FakeAudio({"artist": ["Audioslave"], "title": ["NA"]})  # bogus title
+    monkeypatch.setattr(mf, "_open_audio", lambda path: (audio, None))
+    changed = mf.repair_file(f"X/youtube/Brother Stoon [{YT_ID}].opus", "youtube", dry_run=False)
+    assert "title=Cochise" in changed
+    assert audio["title"] == ["Cochise"]
+
+
+def test_repair_file_overwrites_bogus_artist(monkeypatch):
+    monkeypatch.setattr(mf, "run_yt_dlp_get_metadata",
+                        lambda url, *a: {"artist": "Real Artist", "title": "Real Title",
+                                         "album": "Alb", "release_year": 2020})
+    audio = _FakeAudio({"artist": ["NA"], "title": ["Good Title"]})  # bogus artist, good title
+    monkeypatch.setattr(mf, "_open_audio", lambda path: (audio, None))
+    changed = mf.repair_file(f"X/youtube/Good Title [{YT_ID}].opus", "youtube", dry_run=False)
+    assert "artist=Real Artist" in changed
+    assert audio["artist"] == ["Real Artist"]
+    assert audio["title"] == ["Good Title"]  # good title untouched
+
+
+def test_repair_file_normalizes_na_album_when_source_has_none(monkeypatch):
+    # Music video: no source album/year, but album tag is the literal 'NA' -> Unknown Album.
+    monkeypatch.setattr(mf, "run_yt_dlp_get_metadata",
+                        lambda url, *a: {"title": "Some Live Thing", "uploader": "Chan"})
+    audio = _FakeAudio({"artist": ["X"], "title": ["Y"], "album": ["NA"]})
+    monkeypatch.setattr(mf, "_open_audio", lambda path: (audio, None))
+    changed = mf.repair_file(f"X/youtube/Y [{YT_ID}].opus", "youtube", dry_run=False)
+    assert "album=Unknown Album" in changed
+    assert audio["album"] == ["Unknown Album"]
+
+
+def test_repair_file_renames_bogus_filename(tmp_path, monkeypatch):
+    d = tmp_path / "Audioslave" / "youtube"
+    d.mkdir(parents=True)
+    f = d / f"NA [{YT_ID}].opus"
+    f.write_text("x")
+    monkeypatch.setattr(mf, "run_yt_dlp_get_metadata",
+                        lambda url, *a: {"artist": "Audioslave", "title": "Cochise",
+                                         "album": "Audioslave", "release_year": 2002})
+    audio = _FakeAudio({"artist": ["Audioslave"], "title": ["NA"]})
+    monkeypatch.setattr(mf, "_open_audio", lambda path: (audio, None))
+    changed = mf.repair_file(str(f), "youtube", dry_run=False)
+    assert (d / f"Cochise [{YT_ID}].opus").exists()
+    assert not f.exists()
+    assert any("rename" in c.lower() or c.startswith("title=") for c in changed)
+
+
+def test_repair_file_dry_run_does_not_rename(tmp_path, monkeypatch):
+    d = tmp_path / "Audioslave" / "youtube"
+    d.mkdir(parents=True)
+    f = d / f"NA [{YT_ID}].opus"
+    f.write_text("x")
+    monkeypatch.setattr(mf, "run_yt_dlp_get_metadata",
+                        lambda url, *a: {"artist": "Audioslave", "title": "Cochise",
+                                         "album": "Audioslave", "release_year": 2002})
+    monkeypatch.setattr(mf, "_open_audio", lambda path: (_FakeAudio({"title": ["NA"]}), None))
+    mf.repair_file(str(f), "youtube", dry_run=True)
+    assert f.exists()  # untouched in dry-run
+    assert not (d / f"Cochise [{YT_ID}].opus").exists()
+
+
+def test_fs_safe_replaces_slash():
+    assert "/" not in mf._fs_safe("AC/DC Live")