fix(changelog): 修复多行 commit message 导致的重复内容问题

- 只取第一行作为 subject，忽略 Co-Authored-By 等后续行
- 修复 sed 正则表达式匹配范围问题

@@ -41,9 +41,10 @@ if ! echo "$COMMIT_MSG" | grep -qE "^([a-z]+)\(([a-z-]+)\): .{1,50}"; then
 fi
 
 # 提取信息
-COMMIT_TYPE=$(echo "$COMMIT_MSG" | sed -E 's/^([a-z]+)\(.*/\1/')
-COMMIT_SCOPE=$(echo "$COMMIT_MSG" | sed -E 's/^[a-z]+\(([a-z-]+)\).*/\1/')
-COMMIT_SUBJECT=$(echo "$COMMIT_MSG" | sed -E 's/^[a-z]+\([a-z-]+\): (.{1,50}).*/\1/')
+# 只取第一行作为 subject，忽略 Co-Authored-By 等后续行
+COMMIT_TYPE=$(echo "$COMMIT_MSG" | head -n 1 | sed -E 's/^([a-z]+)\(.*/\1/')
+COMMIT_SCOPE=$(echo "$COMMIT_MSG" | head -n 1 | sed -E 's/^[a-z]+\(([a-z-]+)\).*/\1/')
+COMMIT_SUBJECT=$(echo "$COMMIT_MSG" | head -n 1 | sed -E 's/^[a-z]+\([a-z-]+\): (.*)$/\1/')
 
 # 类型映射到中文
 case "$COMMIT_TYPE" in