fix: resolve CI test failures — add missing functions, fix stale tests (#9483)

Production fixes:
- Add clear_session_context() to hermes_logging.py (fixes 48 teardown errors)
- Add clear_session() to tools/approval.py (fixes 9 setup errors)
- Add SyncError M_UNKNOWN_TOKEN check to Matrix _sync_loop (bug fix)
- Fall back to inline api_key in named custom providers when key_env
  is absent (runtime_provider.py)

Test fixes:
- test_memory_user_id: use builtin+external provider pair, fix honcho
  peer_name override test to match production behavior
- test_display_config: remove TestHelpers for non-existent functions
- test_auxiliary_client: fix OAuth tokens to match _is_oauth_token
  patterns, replace get_vision_auxiliary_client with resolve_vision_provider_client
- test_cli_interrupt_subagent: add missing _execution_thread_id attr
- test_compress_focus: add model/provider/api_key/base_url/api_mode
  to mock compressor
- test_auth_provider_gate: add autouse fixture to clean Anthropic env
  vars that leak from CI secrets
- test_opencode_go_in_model_list: accept both 'built-in' and 'hermes'
  source (models.dev API unavailable in CI)
- test_email: verify email Platform enum membership instead of source
  inspection (build_channel_directory now uses dynamic enum loop)
- test_feishu: add bot_added/bot_deleted handler mocks to _Builder
- test_ws_auth_retry: add AsyncMock for sync_store.get_next_batch,
  add _pending_megolm and _joined_rooms to Matrix adapter mocks
- test_restart_drain: monkeypatch-delete INVOCATION_ID (systemd sets
  this in CI, changing the restart call signature)
- test_session_hygiene: add user_id to SessionSource
- test_session_env: use relative baseline for contextvar clear check
  (pytest-xdist workers share context)

hermes_cli/runtime_provider.py

@@ -287,6 +287,9 @@ def _get_named_custom_provider(requested_provider: str) -> Optional[Dict[str, An
             # Resolve the API key from the env var name stored in key_env
             key_env = str(entry.get("key_env", "") or "").strip()
             resolved_api_key = os.getenv(key_env, "").strip() if key_env else ""
+            # Fall back to inline api_key when key_env is absent or unresolvable
+            if not resolved_api_key:
+                resolved_api_key = str(entry.get("api_key", "") or "").strip()
 
             if requested_norm in {ep_name, name_norm, f"custom:{name_norm}"}:
                 # Found match by provider key