test(tui): fix stale mocks + xdist flakes in TUI test suite

All 61 TUI-related tests green across 3 consecutive xdist runs.

tests/tui_gateway/test_protocol.py:
- rename `get_messages` → `get_messages_as_conversation` on mock DB (method
  was renamed in the real backend, test was still stubbing the old name)
- update tool-message shape expectation: `{role, name, context}` matches
  current `_history_to_messages` output, not the legacy `{role, text}`

tests/hermes_cli/test_tui_resume_flow.py:
- `cmd_chat` grew a first-run provider-gate that bailed to "Run: hermes
  setup" before `_launch_tui` was ever reached; 3 tests stubbed
  `_resolve_last_session` + `_launch_tui` but not the gate
- factored a `main_mod` fixture that stubs `_has_any_provider_configured`,
  reused by all three tests

tests/test_tui_gateway_server.py:
- `test_config_set_personality_resets_history_and_returns_info` was flaky
  under xdist because the real `_write_config_key` touches
  `~/.hermes/config.yaml`, racing with any other worker that writes
  config. Stub it in the test.

tests/hermes_cli/test_model_validation.py

@@ -370,6 +370,8 @@ class TestCopilotNormalization:
         assert opencode_model_api_mode("opencode-zen", "minimax-m2.5") == "chat_completions"
 
     def test_opencode_go_api_modes_match_docs(self):
+        assert opencode_model_api_mode("opencode-go", "glm-5.1") == "chat_completions"
+        assert opencode_model_api_mode("opencode-go", "opencode-go/glm-5.1") == "chat_completions"
         assert opencode_model_api_mode("opencode-go", "glm-5") == "chat_completions"
         assert opencode_model_api_mode("opencode-go", "opencode-go/glm-5") == "chat_completions"
         assert opencode_model_api_mode("opencode-go", "kimi-k2.5") == "chat_completions"