Keep the own-policy fail-closed hardening from PR #45444, but still trust WeCom groups.<id>.allow_from because the adapter already checked that sender allowlist before dispatching to gateway auth.
Own-policy adapters (WhatsApp, WeCom, Weixin, QQBot, Yuanbao) default dm_policy/group_policy to "open", which forwards every sender. The gateway's adapter-trust shortcut in _is_user_authorized blanket-trusted those platforms when no env allowlist was set, so an operator who enabled one with only credentials authorized the entire external network -- the fail-open SECURITY.md section 2.6 forbids ("an allowlist is required for every enabled network-exposed adapter").
Trust the adapter only when its effective policy for the chat type is an actual "allowlist" restriction (the case #34515 was protecting). "open"/"pairing"/anything else falls through to default-deny, where {PLATFORM}_ALLOW_ALL_USERS / GATEWAY_ALLOW_ALL_USERS and the pairing flow remain the explicit opt-ins.
Compare source.role_authorized with 'is True' so a MagicMock source
(test fixtures that build bare runners via object.__new__) doesn't
auto-truthy through the gate. The real SessionSource field is a bool,
so production behavior is unchanged. Fixes test_signal_in_allowlist_maps.
DISCORD_ALLOWED_ROLES was checked by the Discord adapter (_is_allowed_user)
but gateway._is_user_authorized only read DISCORD_ALLOWED_USERS, so
role-authorized users were rejected with "Unauthorized user" at the
gateway layer despite passing the adapter gate.
- Add role_authorized: bool = False to SessionSource
- Add role_authorized param to build_source (base.py)
- Compute _role_authorized in on_message when user passes via role not user ID
- Thread _role_authorized through _handle_message -> build_source
- Check source.role_authorized early in _is_user_authorized (run.py)
Fixes#33952
Lift the 4 inbound-message authorization methods out of GatewayRunner into
gateway/authz_mixin.py:GatewayAuthorizationMixin. Behavior-neutral; gateway/run.py
16200 -> 15812 LOC.
Methods moved (~389 LOC): _is_user_authorized, _get_unauthorized_dm_behavior,
_adapter_dm_policy, _adapter_enforces_own_access_policy. The two adapter-policy
helpers are private to _is_user_authorized, so the cluster is fully self-contained
(zero outside-cluster self.method calls after the lift). All self.* calls resolve
unchanged via the MRO (GatewayRunner(GatewayAuthorizationMixin, ...)).
Import split: 6 neutral deps (os, Optional, Platform, SessionSource, the two
whatsapp_identity helpers) at the mixin module top; the module-level logger is
imported lazily inside _is_user_authorized (from gateway.run import logger) so
the mixin never imports gateway.run at module scope -> no cycle. The lazy import
preserves the exact logger name (gateway.run) so log records are unchanged.
