Fix code quality: trailing whitespace, unused imports, clippy warnings

- Fix trailing whitespace in kex.rs and s3.rs
- Add missing KexProposal import in kex_complete.rs
- Auto-fix clippy warnings across all crates
- All 153 tests pass

markbase-core/src/security_audit/auth_security.rs

@@ -12,20 +12,22 @@ fn get_test_provider() -> Arc<dyn DataProvider> {
 #[test]
 fn test_password_authentication_brute_force_prevention() {
     let provider = get_test_provider();
-    
+
     assert!(provider.check_password("demo", "demo123").unwrap());
     assert!(!provider.check_password("demo", "wrongpassword").unwrap());
     assert!(!provider.check_password("demo", "").unwrap());
-    assert!(!provider.check_password("__nonexistent__", "anypassword").unwrap());
+    assert!(!provider
+        .check_password("__nonexistent__", "anypassword")
+        .unwrap());
 }
 
 #[test]
 fn test_publickey_authentication_security() {
     let provider = get_test_provider();
-    
+
     let keys = provider.get_public_keys("demo").unwrap();
     assert!(keys.is_empty() || keys.len() >= 0);
-    
+
     let keys = provider.get_public_keys("__nonexistent__").unwrap();
     assert!(keys.is_empty());
 }
@@ -33,10 +35,10 @@ fn test_publickey_authentication_security() {
 #[test]
 fn test_user_status_check() {
     let provider = get_test_provider();
-    
+
     let user = provider.get_user("demo").unwrap();
     assert!(user.is_some());
-    
+
     let user = provider.get_user("demo").unwrap();
     if let Some(u) = user {
         assert_eq!(u.status, 1);
@@ -46,16 +48,16 @@ fn test_user_status_check() {
 #[test]
 fn test_home_dir_security() {
     let provider = get_test_provider();
-    
+
     let home = provider.get_home_dir("demo").unwrap();
     assert!(home.is_some());
-    
+
     let home = provider.get_home_dir("__nonexistent__").unwrap();
     assert!(home.is_none());
-    
+
     if let Some(home_path) = provider.get_home_dir("demo").unwrap() {
         assert!(!home_path.contains(".."));
         assert!(!home_path.starts_with("/etc"));
         assert!(!home_path.starts_with("/root"));
     }
-}
+}