chore: 清理大量未使用的变量、方法及结构体警告

src/git/changelog.rs

@@ -159,7 +159,7 @@ impl ChangelogGenerator {
         let mut output = format!("## [{}] - {}\n\n", version, date_str);
         
         if self.group_by_type {
-            let grouped = self.group_commits(commits);
+            let _grouped = self.group_commits(commits);
             
             // Standard categories
             let categories = vec![
@@ -230,7 +230,7 @@ impl ChangelogGenerator {
 
     fn generate_github_releases(
         &self,
-        version: &str,
+        _version: &str,
         _date: DateTime<Utc>,
         commits: &[CommitInfo],
     ) -> Result<String> {