fix: 全量代码审计修复—安全/死代码/错误处理/配置净化

P0 安全修复:
  - 支付宝回调验签 (alipay_notify BTreeMap + rsa2_verify)
  - JWT fallback 'default_secret' 改为 .expect() (panic保底)
  - 安全响应头中间件 (CSP/X-Frame-Options/HSTS)

P1 死代码清理:
  - 移除孤儿文件 src/alipay.rs (284行, 无mod注册)
  - 移除Cargo未使用依赖 (actix-files/error/log/hex/digest)
  - log::info! → tracing::info! (auth.rs)
  - 移除 config.rs server_host + 3个TOML定义

P1 质量修复:
  - 修复 weather.rs unwrap() → unwrap_or
  - 修复 auth.rs+payment.rs 错误吞咽 (add tracing::warn)
  - 修复 main.rs 3x parse().unwrap → unwrap_or

P3 运维:
  - 新增 scripts/backup-db.sh (定时备份用)
  - 新增 README.md (快速入门文档)
  - deploy.sh 集成 backup-db.sh 上传

Cargo.toml

@@ -4,17 +4,14 @@ version = "0.3.0"
 edition = "2024"
 
 [dependencies]
-actix-files = "0.6.8"
 actix-web = {version = "4.11.0", features=["openssl"]}
 chrono = {version = "0.4.41", features=["serde"]}
 dotenvy = "0.15.7"
 tracing = "0.1"
 tracing-subscriber = { version = "0.3", features = ["env-filter", "json"] }
 tracing-appender = "0.2"
-error = "0.1.9"
 include_dir = "0.7.4"
 jsonwebtoken = "9.3.1"
-log = "0.4.28"
 openssl = "0.10.73"
 rand = "0.8"
 reqwest = { version = "0.12.23", features=["json"]}
@@ -28,8 +25,6 @@ base64 = "0.22"
 rsa = { version = "0.9", features = ["pem", "sha2"] }
 pkcs8 = "0.10"
 sha2 = "0.10"
-hex = "0.4"
-digest = "0.10"
 
 [dev-dependencies]
 tokio = { version = "1", features = ["full"] }