fix(tests): resolve CI test failures — pool auto-seeding, stale assertions, mock isolation

Salvaged from PR #10643 by kshitijk4poor, updated for current main.

Root causes fixed:
1. Telegram xdist mock pollution — new tests/gateway/conftest.py with shared
   mock that runs at collection time (prevents ChatType=None caching)
2. VIRTUAL_ENV env var leak — monkeypatch.delenv in _detect_venv_dir tests
3. Copilot base_url missing — add fallback in _resolve_runtime_from_pool_entry
4. Stale vision model assertion — zai now uses glm-5v-turbo
5. Reasoning item id intentionally stripped — assert 'id' not in (store=False)
6. Context length warning unreachable — pass base_url to AIAgent in test
7. Kimi provider label updated — 'Kimi / Kimi Coding Plan' matches models.py
8. Google Workspace calendar tests — rewritten for current production code,
   properly mock subprocess on api_module, removed stale +agenda assertions
9. Credential pool auto-seeding — mock _select_pool_entry / _resolve_auto /
   _import_codex_cli_tokens to prevent real credentials from leaking into tests

tests/hermes_cli/test_model_validation.py

@@ -163,7 +163,7 @@ class TestNormalizeProvider:
 class TestProviderLabel:
     def test_known_labels_and_auto(self):
         assert provider_label("anthropic") == "Anthropic"
-        assert provider_label("kimi") == "Kimi / Moonshot"
+        assert provider_label("kimi") == "Kimi / Kimi Coding Plan"
         assert provider_label("copilot") == "GitHub Copilot"
         assert provider_label("copilot-acp") == "GitHub Copilot ACP"
         assert provider_label("auto") == "Auto"