chore: 修复 clippy 错误（loop never loops → if-let）并应用自动修复

src/tools/approval.rs

@@ -215,12 +215,11 @@ impl ApprovalManager {
 
         let mut map = self.pending.lock().await;
         for (uid, i, _) in expired.iter().rev() {
-            if let Some(entries) = map.get_mut(uid) {
-                if *i < entries.len() {
+            if let Some(entries) = map.get_mut(uid)
+                && *i < entries.len() {
                     let entry = entries.remove(*i);
                     let _ = entry.sender.send(ApprovalDecision::Expired);
                 }
-            }
         }
         map.retain(|_, v| !v.is_empty());
     }