WeComAdapter mixed in OwnAccessPolicyMixin without ALLOW_ALL_ENV_PREFIX, so
_allow_all_env_names() read "_ALLOW_ALL_USERS" and every open-DM WeCom deployment
(setup still writes WECOM_ALLOW_ALL_USERS) silently denied all DMs.
- WeComAdapter.ALLOW_ALL_ENV_PREFIX = "WECOM"
- OwnAccessPolicyMixin.__init_subclass__ raises TypeError on an empty prefix so the
omission cannot ship again (every other host already sets one).
- Parity test now runs a third matrix row that sets each host's own
<PREFIX>_ALLOW_ALL_USERS; the GATEWAY-only row is why this slipped through.
Sabotage: prefix removed -> [platform] row fails even with the guard reverted.
7370c82c2d