feat: 集成 Sentry 错误监控 + 前端错误上报中继

后端:
  - Cargo.toml 添加 sentry/sentry-actix/sentry-tracing (v0.48)
  - main.rs 条件初始化 Sentry（SENTRY_DSN 环境变量控制）
  - 新增 handlers/sentry.rs — POST /api/sentry/events 前端中继端点
  - sentry-actix 全局中间件 + sentry-tracing 自动捕获 tracing::error!
  - .env.example 添加 SENTRY_DSN / SENTRY_TRACES_SAMPLE_RATE 配置

前端:
  - 新增 utils/sentryReporter.ts (批量上报/防抖/开发环境跳过)
  - app.ts 全局错误处理接入 Sentry (wx.onError/onUnhandledRejection/onPageNotFound)

Sentry 未配置 DSN 时完全无操作，无性能开销

Cargo.toml

@@ -10,6 +10,9 @@ dotenvy = "0.15.7"
 tracing = "0.1"
 tracing-subscriber = { version = "0.3", features = ["env-filter", "json"] }
 tracing-appender = "0.2"
+sentry = "0.48"
+sentry-actix = "0.48"
+sentry-tracing = "0.48"
 include_dir = "0.7.4"
 jsonwebtoken = "9.3.1"
 openssl = "0.10.73"