fix: 按评审报告止血支付漏洞并加固授权链路

废除浏览器回跳自助结算，通用 webhook 强制密钥鉴权，Waffo 支持验签与未知事件忽略；重构订单状态机/激活占座/SQLite WAL，并补备份、readyz、限流与前端导出/登录页安全修复。

Co-authored-by: Cursor <cursoragent@cursor.com>

Dockerfile

@@ -18,7 +18,7 @@ COPY frontend/ ./
 RUN npm run build
 
 # ==================== Stage 2: Backend ====================
-FROM golang:1.24-bookworm AS backend-builder
+FROM golang:1.25-bookworm AS backend-builder
 
 WORKDIR /src
 ENV GOPROXY=https://goproxy.cn,direct
@@ -61,6 +61,6 @@ VOLUME ["/data"]
 EXPOSE 9001
 
 HEALTHCHECK --interval=15s --timeout=3s --start-period=10s --retries=5 \
-  CMD curl -fsS "http://127.0.0.1:${PORT}/health" || exit 1
+  CMD curl -fsS "http://127.0.0.1:${PORT}/readyz" || exit 1
 
 ENTRYPOINT ["/app/opsx-licence"]