fix(desktop): launch the installed Hermes.app from hermes desktop

On macOS `hermes desktop` launched the release/ bundle even when an
installed Hermes.app existed, so the app ran from two paths (two Dock
icons, TCC grants keyed to a different bundle) while the one Finder opens
stayed stale. Refresh the installed copies first and launch the one that
now matches the checkout build; release/ stays the fallback.

hermes_cli/main_desktop.py

@@ -953,6 +953,15 @@ def _install_rebuilt_desktop_app(desktop_dir: Path) -> tuple[list[Path], list[st
         rebuilt_exe.parents[2], _installed_desktop_apps(), running=_running_macos_app_bundles())
 
 
+def _refresh_installed_desktop_apps(desktop_dir: Path) -> None:
+    """Install the rebuilt bundle over stale installed copies and report each outcome."""
+    installed, problems = _install_rebuilt_desktop_app(desktop_dir)
+    for app in installed:
+        print(f"  ✓ Installed the rebuilt Desktop app at {app}")
+    for problem in problems:
+        print(f"  ⚠ {problem}")
+
+
 def _update_owned_macos_bundles(candidates: list[Path]) -> list[Path]:
     """The existing bundles in *candidates* that only ``hermes update`` keeps current (#52339).
 
@@ -988,6 +997,25 @@ def _installed_desktop_apps() -> list[Path]:
     return _update_owned_macos_bundles(packaged_gui_app_paths())
 
 
+def _installed_desktop_launch_target(desktop_dir: Path, packaged_executable: Path) -> Path:
+    """The executable ``hermes desktop`` launches: the installed app once it IS the checkout build.
+
+    Finder, the Dock and Spotlight open the installed ``Hermes.app``; launching the ``release/``
+    bundle beside it ran the same app from a second path while the installed copy went stale
+    (#52339). Refresh the installed copies, then launch the first one that matches the checkout
+    build. The checkout bundle stays the fallback: nothing installed, or a copy that is running
+    or could not be replaced.
+    """
+    if sys.platform != "darwin":
+        return packaged_executable
+    _refresh_installed_desktop_apps(desktop_dir)
+    rebuilt_hash = _app_asar_hash(packaged_executable.parents[2])
+    for app in _installed_desktop_apps():
+        if rebuilt_hash is not None and _app_asar_hash(app) == rebuilt_hash:
+            return app / "Contents" / "MacOS" / "Hermes"
+    return packaged_executable
+
+
 def _install_rebuilt_macos_bundles(
         rebuilt_app: Path, candidates: list[Path], *, running: set[Path]) -> tuple[list[Path], list[str]]:
     """Stage-and-swap ``rebuilt_app`` over each existing bundle in ``candidates`` whose ``app.asar``
@@ -1574,7 +1602,8 @@ def cmd_gui(args: argparse.Namespace):
             print(f"✗ Desktop package build completed but no launchable app was found at: {desktop_dir / 'release'}")
             print("  Expected an unpacked Electron app for the current OS.")
             sys.exit(1)
-        launch_command = _packaged_desktop_launch_command(packaged_executable)
+        launch_command = _packaged_desktop_launch_command(
+            _installed_desktop_launch_target(desktop_dir, packaged_executable))
         launch_command.extend(config_electron_flags)
     if getattr(args, "local", False):
         launch_command.append("--local")

hermes_cli/source_build.py

@@ -121,7 +121,7 @@ def build_update_products(project_root: Path, *, desktop: bool) -> None:
         publish_stage("Building the web UI")
         build_source_web(project_root, env=env)
     if desktop:
-        from hermes_cli.main_desktop import _install_rebuilt_desktop_app, build_prepared_desktop
+        from hermes_cli.main_desktop import _refresh_installed_desktop_apps, build_prepared_desktop
 
         publish_stage("Building the desktop app")
         build_prepared_desktop(
@@ -130,11 +130,7 @@ def build_update_products(project_root: Path, *, desktop: bool) -> None:
         )
         # A current release/ can still sit beside a stale installed copy (an earlier
         # update rebuilt but never installed); healing must not wait for the next build.
-        installed, problems = _install_rebuilt_desktop_app(project_root / "apps/desktop")
-        for app in installed:
-            print(f"  ✓ Installed the rebuilt Desktop app at {app}")
-        for problem in problems:
-            print(f"  ⚠ {problem}")
+        _refresh_installed_desktop_apps(project_root / "apps/desktop")
     # A configured memory provider that no longer ships in core is installed from the
     # catalog for every profile home sharing this venv (config, data and tool names
     # unchanged). The update must finish even if the migration blows up.

tests/hermes_cli/test_gui_command.py

@@ -176,6 +176,42 @@ def test_source_launch_reads_bom_electron_path_without_provisioning(tmp_path, mo
     assert len(calls) == 1
 
 
+def _stamped_macos_bundle(app: Path, asar: bytes) -> Path:
+    (app / "Contents" / "MacOS").mkdir(parents=True)
+    (app / "Contents" / "MacOS" / "Hermes").write_bytes(b"\xcf\xfa\xed\xfe")
+    (app / "Contents" / "Resources").mkdir()
+    (app / "Contents" / "Resources" / "app.asar").write_bytes(asar)
+    (app / "Contents" / "Resources" / "install-stamp.json").write_text('{"updateMechanism": "self"}')
+    return app
+
+
+@pytest.mark.platforms("macos")
+def test_packaged_launch_opens_the_refreshed_installed_app(tmp_path, monkeypatch):
+    """#52339: Finder and the Dock open the installed Hermes.app, so ``hermes desktop`` must launch
+    that copy (brought up to the checkout build) instead of a second bundle under release/."""
+    import shutil
+
+    root = _make_desktop_tree(tmp_path)
+    _stamped_macos_bundle(root / "apps" / "desktop" / "release" / "mac-arm64" / "Hermes.app", b"checkout build")
+    installed = _stamped_macos_bundle(tmp_path / "Applications" / "Hermes.app", b"stale build")
+    monkeypatch.setattr("hermes_cli.gui_uninstall.packaged_gui_app_paths", lambda: [installed])
+    monkeypatch.setattr("hermes_constants.get_default_hermes_root", lambda **kw: tmp_path)  # root is its hermes-agent
+    monkeypatch.setattr(main_desktop, "_stage_macos_bundle_copy", lambda src, dst: shutil.copytree(src, dst, symlinks=True))
+    monkeypatch.setattr(main_desktop, "_running_macos_app_bundles", lambda: set())
+    monkeypatch.setattr(cli_main, "PROJECT_ROOT", root)
+    monkeypatch.setattr(main_desktop, "_desktop_launch_env", lambda args: ({}, []))
+    calls = []
+    monkeypatch.setattr(main_desktop.subprocess, "run",
+                        lambda cmd, **kw: calls.append(cmd) or subprocess.CompletedProcess(cmd, 0))
+
+    with pytest.raises(SystemExit) as exit_info:
+        main_desktop.cmd_gui(_ns(skip_build=True))
+
+    assert exit_info.value.code == 0
+    assert calls == [[str(installed / "Contents" / "MacOS" / "Hermes")]]
+    assert (installed / "Contents" / "Resources" / "app.asar").read_bytes() == b"checkout build"
+
+
 def test_packaged_renderer_bom_does_not_bypass_entry_validation(tmp_path):
     import json
     import struct