- load_gateway_config (536 LOC) is now a thin orchestrator: legacy gateway.json
-> config_loader.load_yaml_layer -> GatewayConfig.from_dict -> env overrides
-> validation. The yaml phase lives in gateway/config_loader.py as small
functions driven by tables: _TOPLEVEL_BRIDGE (23 top-level/nested
gateway.<key> bridges with 5 fallback modes), _SHARED_KEYS (28 per-platform
keys copied into extra, with per-platform restrictions and transforms) and
_PORT_BRIDGE_KEYS. Logger name kept as "gateway.config".
- GatewayConfig.from_dict: shared pick()/key_label() helpers replace the
repeated "top-level key present else nested gateway.<key>" blocks; warning
order preserved.
- _normalize_unauthorized_dm_behavior / _normalize_notice_delivery unified into
_normalize_choice; _ensure_platform_extra_dict -> _dict_slot (also used by
persist_home_channel); _getenv_int removed (dead since the env pass moved to
config_env, which has its own _int_or).
- Platform._missing_: one _add_pseudo_member helper for both branches.
- Single warning sites in _coerce_optional_positive_int and
coerce_systemd_watchdog_seconds; _validate_gateway_config placeholder pass
flattened; small to_dict/getter collapses. Ruff F401/SIM102 clean.
- tests/hermes_cli/test_config_read_guard.py: allowlist gateway/config_loader.py
(same owner as gateway/config.py — the extracted load_gateway_config phase).
gateway/config.py 2684 -> 1319 LOC (-50.9%); largest function now
GatewayConfig.from_dict at 119 LOC. Resolved-config parity: 160 cells
(16 yaml fixtures x 10 env sets) byte-identical to the integration base,
including captured log records and stderr.
Teknium