test(desktop): neutralize the Linux desktop-entry install in the Ctrl-C exit test

Patching hermes_cli.main.subprocess.run swaps the shared stdlib module's
attribute, so every subprocess.run in the process raises. On Linux the
best-effort desktop-entry install runs refresh_desktop_databases via
subprocess.run BEFORE the attached launch — outside the KeyboardInterrupt
handler under test — so the mock's interrupt aborted the whole pytest
process (CI: 'tests/hermes_cli/test_gui_command.py:1070:
KeyboardInterrupt'). Neutralize _register_linux_desktop_entry the way the
other foreground tests in this file do.

tests/hermes_cli/test_gui_command.py

@@ -1125,6 +1125,12 @@ def test_gui_foreground_launch_ctrl_c_exits_cleanly(tmp_path, monkeypatch, capsy
     """
     root = _make_desktop_tree(tmp_path)
     monkeypatch.setattr(cli_main, "PROJECT_ROOT", root)
+    # Patching hermes_cli.main.subprocess.run swaps the shared stdlib module's
+    # attribute, so EVERY subprocess.run in the process raises. On Linux the
+    # best-effort desktop-entry install runs refresh_desktop_databases →
+    # subprocess.run BEFORE the attached launch — outside the KeyboardInterrupt
+    # handler under test — so neutralize it like the other foreground tests do.
+    monkeypatch.setattr(main_desktop, "_register_linux_desktop_entry", lambda **kw: None)
     packaged_exe = _make_packaged_executable(root, monkeypatch)
     ok = subprocess.CompletedProcess([], 0)