fix(clients): flatten scoped remote output

- Render explicit --remote clients results with profile-only labels.

- Suppress remote host group headers for scoped client queries.

- Keep global and mixed client listings grouped by host.

- Update client and CLI tests for scoped remote rendering.

- Bump browser-cli and extension versions to 0.16.5.

tests/test_client.py

@@ -681,7 +681,8 @@ def test_collect_browser_clients_with_explicit_remote_lists_all_targets(monkeypa
 
   rows = collect_browser_clients(remote="browser-host.example:8765", registry_path=tmp_path / "missing-registry.json")
 
-  assert [row["profile"] for row in rows] == ["browser-host.example:main", "browser-host.example:work"]
+  assert [row["profile"] for row in rows] == ["main", "work"]
+  assert [row.get("profileGroup") for row in rows] == [None, None]
   assert [row["name"] for row in rows] == ["Chrome", "Firefox"]
 
 def test_collect_browser_clients_with_explicit_remote_and_browser_filters_target(monkeypatch, tmp_path):
@@ -696,7 +697,8 @@ def test_collect_browser_clients_with_explicit_remote_and_browser_filters_target
 
   rows = collect_browser_clients(remote="browser-host.example:8765", browser_alias="work", registry_path=tmp_path / "missing-registry.json")
 
-  assert [row["profile"] for row in rows] == ["browser-host.example:work"]
+  assert [row["profile"] for row in rows] == ["work"]
+  assert rows[0].get("profileGroup") is None
 
 def test_collect_browser_clients_falls_back_when_version_unknown(monkeypatch, tmp_path):
   """An older remote (no advertised version) still triggers a clients.list query."""