feat(server): load musicfetch binary as importable module

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

server/mf.py

@@ -0,0 +1,24 @@
+"""Loads the sibling standalone `musicfetch` script (no .py extension) as a
+module and re-exports the symbols the API reuses. This is the single seam
+between the REST API and the CLI; musicfetch itself is unchanged."""
+import importlib.machinery
+import importlib.util
+import os
+
+_HERE = os.path.dirname(os.path.abspath(__file__))
+_MF_PATH = os.environ.get("MUSICFETCH_BIN", os.path.join(_HERE, "..", "musicfetch"))
+
+# spec_from_file_location returns None for extension-less files, so use
+# SourceFileLoader directly to handle the bare `musicfetch` binary.
+_loader = importlib.machinery.SourceFileLoader("musicfetch_core", _MF_PATH)
+_spec = importlib.util.spec_from_loader("musicfetch_core", _loader)
+_mod = importlib.util.module_from_spec(_spec)
+_spec.loader.exec_module(_mod)  # safe: musicfetch guards main() behind __main__
+
+Hit = _mod.Hit
+build_combined_hits = _mod.build_combined_hits
+pick = _mod.pick
+act_youtube = _mod.act_youtube
+act_lidarr_album = _mod.act_lidarr_album
+act_lidarr_artist = _mod.act_lidarr_artist
+QUALITY_CHOICES = _mod.QUALITY_CHOICES

tests/test_mf_loader.py

@@ -0,0 +1,15 @@
+def test_mf_reexports_musicfetch_symbols():
+    from server import mf
+    assert hasattr(mf, "Hit")
+    assert callable(mf.build_combined_hits)
+    assert callable(mf.pick)
+    assert callable(mf.act_youtube)
+    assert callable(mf.act_lidarr_album)
+    assert callable(mf.act_lidarr_artist)
+
+
+def test_mf_hit_constructs():
+    from server import mf
+    h = mf.Hit(source="youtube", kind="track", title="x", artist="y")
+    assert h.source == "youtube"
+    assert h.artist == "y"