feat(cli): 优化 log 子命令并引入 LogLevel 强类型解析,重构 commands.lua 注册表解析与校验逻辑

- 调整 LogLevel 的 FromStr 错误类型为 String，适配 clap 的 value_parser
- log 子命令直接绑定 LogLevel 枚举，消除硬编码校验与类型转换
- 规范化日志级别更新与配置读取逻辑
- handler 类型有 Function 改为 String

mirror-core/Cargo.toml

@@ -0,0 +1,16 @@
+[package]
+name = "mirror-core"
+version = { workspace = true }
+edition = { workspace = true }
+
+[dependencies]
+anyhow = { workspace = true }
+mlua = { workspace = true }
+dunce = { workspace = true }
+tinyjson = { workspace = true }
+windows-sys = { workspace = true }
+serde = { workspace = true }
+# 日志
+tracing = { workspace = true }
+tracing-subscriber = { workspace = true }
+tracing-appender = { workspace = true }