fix(安全): 修复依赖漏洞并强化安全扫描

主要改动：
- 固定 Go 1.25.5 与 CI 校验并更新扫描流程
- 升级 quic-go、x/crypto、req 等依赖并通过 govulncheck
- 强化 JWT 校验、TLS 配置与 xlsx 动态加载
- 新增审计豁免清单与校验脚本

.github/audit-exceptions.yml

@@ -0,0 +1,16 @@
+version: 1
+exceptions:
+  - package: xlsx
+    advisory: "GHSA-4r6h-8v6p-xvw6"
+    severity: high
+    reason: "Admin export only; switched to dynamic import to reduce exposure (CVE-2023-30533)"
+    mitigation: "Load only on export; restrict export permissions and data scope"
+    expires_on: "2026-04-05"
+    owner: "security@your-domain"
+  - package: xlsx
+    advisory: "GHSA-5pgg-2g8v-p4x9"
+    severity: high
+    reason: "Admin export only; switched to dynamic import to reduce exposure (CVE-2024-22363)"
+    mitigation: "Load only on export; restrict export permissions and data scope"
+    expires_on: "2026-04-05"
+    owner: "security@your-domain"