refactor: skill.rs → types.rs 重命名

类型定义重命名，消除过时的 'skill' 概念

src/tools/weather.rs

@@ -19,7 +19,7 @@ use std::collections::HashMap;
 use std::sync::Mutex;
 use std::time::{Duration, Instant};
 
-use crate::tools::skill::{RiskLevel, SkillResult, SkillSpec};
+use crate::tools::types::{RiskLevel, SkillResult, SkillSpec};
 
 // ═══════════════════════════════════════════════
 // JWT 认证