enh: channel read/write perm

backend/open_webui/utils/access_control.py

@@ -110,9 +110,13 @@ def has_access(
     type: str = "write",
     access_control: Optional[dict] = None,
     user_group_ids: Optional[Set[str]] = None,
+    strict: bool = True,
 ) -> bool:
     if access_control is None:
-        return type == "read"
+        if strict:
+            return type == "read"
+        else:
+            return True
 
     if user_group_ids is None:
         user_groups = Groups.get_groups_by_member_id(user_id)