feat: add heal cut editor action

tests/test_ui_structure.py

@@ -795,8 +795,8 @@ def test_audio_editor_dialog_scaffold(win):
     assert dlg._current() == "/nonexistent.wav"
     # widgets present
     assert dlg._wave is not None
-    for name in ("_btn_delete", "_btn_silence", "_btn_reverse", "_btn_trim",
-                 "_btn_undo", "_btn_redo", "_btn_save_as"):
+    for name in ("_btn_heal_cut", "_btn_delete", "_btn_silence", "_btn_reverse",
+                 "_btn_trim", "_btn_undo", "_btn_redo", "_btn_save_as"):
         assert isinstance(getattr(dlg, name), QPushButton)
     # undo disabled at the base version, redo disabled with no forward history
     assert not dlg._btn_undo.isEnabled()
@@ -821,6 +821,28 @@ def test_editor_delete_builds_command(win, tmp_path, monkeypatch):
     assert seen["inp"] == str(src) and seen["s"] == 1.0 and seen["e"] == 3.0
 
 
+def test_editor_heal_cut_builds_command(win, tmp_path, monkeypatch):
+    import main as m, pytest
+    src = tmp_path / "v0.wav"
+    src.write_bytes(b"")
+    dlg = m.AudioEditorDialog(str(src), parent=win)
+    dlg._clip_dur = 6.0
+    dlg._wave.set_view(0.0, 6.0)
+    dlg._wave.set_selection(2.0, 3.0)
+    seen = {}
+    class _Stop(Exception):
+        pass
+    def fake(inp, s, e, out):
+        seen.update(inp=inp, s=s, e=e, out=out)
+        raise _Stop
+    monkeypatch.setattr(m, "build_audio_heal_delete_command", fake)
+    with pytest.raises(_Stop):
+        dlg._on_heal_cut()
+    assert seen["inp"] == str(src)
+    assert seen["s"] == 2.0 and seen["e"] == 3.0
+    assert seen["out"].endswith(".wav")
+
+
 def test_editor_op_no_region_is_safe(win, tmp_path, monkeypatch):
     import main as m
     src = tmp_path / "v0.wav"; src.write_bytes(b"")