fix(desktop): keep named-profile desktop backends per-profile (#44510)

Desktop spawns its dashboard backend with `--profile <name>` and
`HERMES_DESKTOP=1`. cmd_dashboard's unified-launch routing treats any
named profile as a request for the shared machine dashboard: it re-execs
as the default profile (dropping HERMES_HOME) or, when one is already
listening, prints "Machine dashboard already running ... Managing profile
'<name>'" and exits 0. Either way the desktop-spawned child exits before
the app sees a ready backend, so Desktop retries forever — the Windows
named-profile boot loop in the post-mortem.

Skip the machine-dashboard reroute when HERMES_DESKTOP=1 so desktop pool
backends stay per-profile (which is what the pool expects). Carved out of
#44478.

Co-authored-by: AJ <yspdev@gmail.com>

hermes_cli/main.py

@@ -10332,6 +10332,8 @@ def cmd_dashboard(args):
         _launch_profile not in ("default", "custom")
         and not getattr(args, "isolated", False)
         and not getattr(args, "open_profile", "")
+        # Desktop pool backends are intentionally per-profile.
+        and os.environ.get("HERMES_DESKTOP") != "1"
     ):
         url = f"http://{args.host or '127.0.0.1'}:{args.port}/?profile={_launch_profile}"
         if _dashboard_listening(args.host, args.port):

tests/hermes_cli/test_dashboard_unified_launch.py

@@ -82,6 +82,29 @@ class TestUnifiedDashboardRouting:
         # Profile HERMES_HOME dropped so the child binds the machine root.
         assert "HERMES_HOME" not in env
 
+    def test_desktop_profile_backend_skips_machine_dashboard_reroute(self, main_mod, monkeypatch):
+        """A desktop-spawned named-profile backend (HERMES_DESKTOP=1) must NOT
+        reroute into the machine dashboard. The reroute re-execs as the default
+        profile and exits, so the desktop never sees a ready backend → boot
+        loop. The guard keeps desktop pool backends per-profile."""
+        monkeypatch.setenv("HERMES_DESKTOP", "1")
+        monkeypatch.setattr(
+            "hermes_cli.profiles.get_active_profile_name", lambda: "worker_x"
+        )
+        listening_calls = []
+        monkeypatch.setattr(
+            main_mod, "_dashboard_listening",
+            lambda host, port: listening_calls.append(1) or False,
+        )
+        execs = []
+        monkeypatch.setattr(main_mod.os, "execvpe", lambda *a, **k: execs.append(a))
+        monkeypatch.setitem(sys.modules, "fastapi", None)
+
+        with pytest.raises((SystemExit, AttributeError, ImportError, TypeError)):
+            main_mod.cmd_dashboard(_args())
+        assert listening_calls == []
+        assert execs == []
+
     def test_isolated_flag_skips_routing(self, main_mod, monkeypatch):
         monkeypatch.setattr(
             "hermes_cli.profiles.get_active_profile_name", lambda: "worker_x"