租户配额与计费：按用户月度 USD 上限 + 建任务/分支/重试准入 402 + 管理/自查端点 + 控制台展示

cloud/db.py

@@ -885,6 +885,10 @@ POSTGRES_SCHEMA = (
     "CREATE UNIQUE INDEX IF NOT EXISTS idx_env_name"
     " ON environments(project_id, name)"
     " WHERE status != 'archived'",
+    "CREATE TABLE IF NOT EXISTS user_quotas("
+    "user_id TEXT PRIMARY KEY, "
+    "quota_usd_micros BIGINT, "
+    "updated_at DOUBLE PRECISION)",
     "CREATE TABLE IF NOT EXISTS summaries("
     "id BIGINT GENERATED BY DEFAULT AS IDENTITY PRIMARY KEY, "
     "project_id TEXT, "