fix(whatsapp): honor dm_policy and group_policy open at the gateway

gateway/platforms/base.py

@@ -1750,8 +1750,8 @@ class BasePlatformAdapter(ABC):
     def enforces_own_access_policy(self) -> bool:
         """Whether this adapter gates inbound access before dispatch.
 
-        Some adapters (WeCom, Weixin, Yuanbao, QQBot) implement a documented
-        config-driven access surface — ``dm_policy`` / ``group_policy`` /
+        Some adapters (WeCom, Weixin, Yuanbao, QQBot, WhatsApp) implement a
+        documented config-driven access surface — ``dm_policy`` / ``group_policy`` /
         ``allow_from`` / ``group_allow_from`` in ``PlatformConfig.extra`` — and
         enforce it at intake: a message is dropped inside the adapter and never
         reaches the gateway unless it already passed that policy.

gateway/platforms/whatsapp.py

@@ -379,6 +379,11 @@ class WhatsAppAdapter(BasePlatformAdapter):
             return True
         return False
 
+    @property
+    def enforces_own_access_policy(self) -> bool:
+        """WhatsApp gates DM/group access at intake via dm_policy/group_policy."""
+        return True
+
     def _is_dm_allowed(self, sender_id: str) -> bool:
         """Check whether a DM from the given sender should be processed."""
         if self._dm_policy == "disabled":