feat(node): recognize WMA and Musepack as audio, read their real tag keys

A real-library scan turned up 250 .wma and 23 .mpc files that the indexer
was silently classifying as "other" — genuinely lost from the Music app,
not a consolidation-rule artifact (checked separately: the grouping logic
itself drops nothing). Both are now indexed as audio and tagged properly:

- WMA has no mutagen "easy" wrapper, so the generic tag reader was reading
  nothing from it at all. Reads the real ASF keys directly instead
  (Title/Author/WM-AlbumTitle/WM-TrackNumber), confirmed against a real
  sample file before writing the mapping.
- Musepack's format auto-detection is unreliable enough (misidentified a
  real .mpc as MP3 in spot checks) that it now always opens by its own
  class instead of guessing from content.
- Filters out another placeholder value found along the way: a French
  ripping tool's auto-generated "Album inconnu (<timestamp>)".

Neither format decodes natively in a browser's <audio> element, so this
gets them correctly visible, tagged, and covered — not yet playable
in-browser. That would need server-side transcoding, deliberately left
out of this change.

1 files changed, 11 insertions, 0 deletions

diff --git a/packages/meshbay-node/tests/test_indexer.py b/packages/meshbay-node/tests/test_indexer.py
index 3eac39e..56571a4 100644
--- a/packages/meshbay-node/tests/test_indexer.py
+++ b/packages/meshbay-node/tests/test_indexer.py
@@ -146,6 +146,17 @@ async def test_type_detection(shared_dir, sk_node, gek):
     assert by_name["manual.pdf"] == "document"
 
 
+def test_type_detection_covers_wma_and_musepack():
+    """
+    Both formats are real audio a real library can contain, even though
+    neither one plays natively in a browser <audio> element — that gap is
+    a separate, later concern (transcoding); being correctly typed and
+    tagged is not the same thing as being playable.
+    """
+    assert indexer_mod._detect_type(Path("track.wma")) == "audio"
+    assert indexer_mod._detect_type(Path("track.mpc")) == "audio"
+
+
 @pytest.mark.asyncio
 async def test_hidden_files_excluded(tmp_path, sk_node, gek):
     d = tmp_path / "dir"