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-smb/src/acl.rs

@@ -28,15 +28,15 @@ impl UserPermission {
             admin_access: admin,
         }
     }
-    
+
     pub fn readonly(username: String) -> Self {
         UserPermission::new(username, true, false, false)
     }
-    
+
     pub fn full_access(username: String) -> Self {
         UserPermission::new(username, true, true, false)
     }
-    
+
     pub fn admin(username: String) -> Self {
         UserPermission::new(username, true, true, true)
     }
@@ -57,28 +57,32 @@ impl AccessControlList {
             max_connections: 10,
         }
     }
-    
+
     pub fn add_user(&mut self, permission: UserPermission) {
-        if let Some(existing) = self.users.iter_mut().find(|u| u.username == permission.username) {
+        if let Some(existing) = self
+            .users
+            .iter_mut()
+            .find(|u| u.username == permission.username)
+        {
             *existing = permission;
         } else {
             self.users.push(permission);
         }
     }
-    
+
     pub fn remove_user(&mut self, username: &str) {
         self.users.retain(|u| u.username != username);
     }
-    
+
     pub fn get_user(&self, username: &str) -> Option<&UserPermission> {
         self.users.iter().find(|u| u.username == username)
     }
-    
+
     pub fn has_access(&self, username: &str, require_write: bool) -> bool {
         if self.guest_access && !require_write {
             return true;
         }
-        
+
         self.get_user(username)
             .map(|u| {
                 if require_write {
@@ -89,4 +93,4 @@ impl AccessControlList {
             })
             .unwrap_or(false)
     }
-}
+}