feat(server): load musicfetch binary as importable module

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

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"