GRM-16: feat: add --force flag to grm remove for unreachable runners

- Add force parameter to RunnerManager.remove() — skips remote Ansible
  playbook and only removes the local registry entry
- Add --force/-f CLI flag to grm remove command
- Add translations for --force help text across all 5 languages
- Add unit tests for force skip and CLI flag propagation
- 118 tests, 100% coverage, pyright clean, ruff clean

tests/unit/test_cli.py

@@ -375,6 +375,27 @@ class TestCLI:
             gitea_url="https://git.example.com",
             mode=None,
             ask_become_pass=False,
+            force=False,
+        )
+
+    @patch("gitea_runner_manager.cli.RunnerManager")
+    def test_remove_force_flag(self, mock_manager_class: MagicMock) -> None:
+        mock_manager = MagicMock()
+        mock_manager_class.return_value = mock_manager
+
+        runner = CliRunner(env={"GITEA_URL": "https://git.example.com"})
+        result = runner.invoke(cli, ["remove", "r1", "--token", "tok", "--force"])
+        assert result.exit_code == 0
+        mock_manager.remove.assert_called_once_with(
+            name="r1",
+            host=None,
+            user=None,
+            key=None,
+            token="tok",
+            gitea_url="https://git.example.com",
+            mode=None,
+            ask_become_pass=False,
+            force=True,
         )
 
     @patch("gitea_runner_manager.cli.RunnerManager")