Import existing LinTunes project

Snapshot of the existing codebase before working through the TASKS.md
backlog. Real library data (data/) and the iTunes import fixture
(itunes-test-library/) are gitignored.

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

tests/test_track_edit.py

@@ -0,0 +1,56 @@
+"""Regression tests for live browser refresh after a Get-Info edit.
+
+The bug: renaming a track's artist left the column browser (and its filter)
+pointing at the old name, so the renamed artist didn't re-sort and clicking it
+returned no tracks. The fix routes a new `track_fields_edited(track_id, fields)`
+signal to the library view, which rebuilds the browser only when a field it
+groups by changed — and leaves play-count/skip bumps alone.
+"""
+
+from lintunes.models import Library, Track
+from lintunes.library_manager import LibraryManager
+from lintunes.gui.library_view import _BROWSER_FIELDS
+
+
+def _manager(tmp_path):
+    track = Track(track_id=1, name="Song", artist="Aardvark",
+                  album="Debut", genre="Rock")
+    library = Library(tracks={1: track})
+    return LibraryManager(library, tmp_path), track
+
+
+def test_edit_emits_changed_fields(qapp, tmp_path):
+    manager, _track = _manager(tmp_path)
+    edits, updates = [], []
+    manager.track_fields_edited.connect(lambda tid, fields: edits.append((tid, fields)))
+    manager.track_updated.connect(updates.append)
+
+    manager.update_track_fields(1, {"artist": "Zz Top"})
+
+    assert edits == [(1, ["artist"])]
+    assert updates == [1]
+    assert _BROWSER_FIELDS.intersection(edits[0][1])  # would refresh the browser
+
+
+def test_no_op_edit_is_silent(qapp, tmp_path):
+    manager, _track = _manager(tmp_path)
+    edits = []
+    manager.track_fields_edited.connect(lambda tid, fields: edits.append((tid, fields)))
+
+    manager.update_track_fields(1, {"artist": "Aardvark"})  # unchanged value
+
+    assert edits == []
+
+
+def test_play_count_does_not_reorganize(qapp, tmp_path):
+    """record_play bumps play_count via track_updated but must NOT emit
+    track_fields_edited, so a finished play never rebuilds the browser."""
+    manager, _track = _manager(tmp_path)
+    edits, updates = [], []
+    manager.track_fields_edited.connect(lambda tid, fields: edits.append((tid, fields)))
+    manager.track_updated.connect(updates.append)
+
+    manager.record_play(1)
+
+    assert edits == []
+    assert updates == [1]