残留批次A：成员删除、PR needs_local_worker 落库、推送 DNS TOCTOU

- 成员删除：DELETE /projects/{id}/members/{user_id}，限 owner 或
  全局管理员，禁删唯一 owner，记 remove_member 审计
  （AuthStore.remove_member + server 分发，沿用 PATCH 守卫口径）
- PR needs_local_worker 落库：非 local 扫到 queued 任务时 CAS
  写行状态为 needs_local_worker；claim/find_open 同步认该状态，
  标记过的行仍可被 local worker 认领、不被搁置；另修
  claim/find_open 对裸 sqlite3 tuple 行的 dict() 兜底
  （TypeError/ValueError）
- 推送 DNS TOCTOU：发送改走建连时解析+判段的连接类，解析
  一次、只拨判过的 IP，Host/SNI 仍为原域名；opener 直接构造
  以排除 ProxyHandler 改写（build_opener 默认会塞代理）

cloud/auth.py

@@ -307,6 +307,25 @@ class AuthStore:
             "%s:%s" % (target_user_id, role),
         )
 
+    def remove_member(self, project_id, actor_user_id, target_user_id):
+        """删成员：只有 owner 能删，否则 raise PermissionError；同时记审计。"""
+        if self._member_role(project_id, actor_user_id) != "owner":
+            raise PermissionError(
+                "only project owner can change members"
+            )
+        self.conn.execute(
+            "DELETE FROM project_members"
+            " WHERE project_id = ? AND user_id = ?",
+            (project_id, target_user_id),
+        )
+        self.conn.commit()
+        self.audit(
+            actor_user_id,
+            project_id,
+            "remove_member",
+            target_user_id,
+        )
+
     def check_permission(self, user_id, project_id, action):
         """检查权限：满足最低角色返回 True，否则 False（含未加入项目）。"""
         min_role = _ACTION_MIN_ROLE.get(action)