fix(留言分頁): 改用 timeline 分頁讀取留言

Gitea 議題留言端點無法可靠處理分頁；改由 timeline 逐頁篩選 comment 事件並去重，讓抽取、整併與 PR 留言流程取得完整集合。

scripts/issue-extract.js

@@ -31,16 +31,15 @@ main(async () => {
   const repo = parseRepo(flags.repo);
   const index = parseIndex(flags.index);
   const issuePath = `/repos/${repo}/issues/${index}`;
-  const commentsPath = `${issuePath}/comments`;
+  const timelinePath = `${issuePath}/timeline`;
 
   if (flags['dry-run']) {
     return {
       dryRun: true,
       repo,
-      index,
       requests: [
         { method: 'GET', path: issuePath },
-        { method: 'GET', path: commentsPath },
+        { method: 'GET', path: timelinePath },
       ],
       note: UNMERGED_COMMENT_NOTE,
     };