fix: 改回 git commit/push，強制 Dockerfile rebuild 確保 git binary 存在

Dockerfile

@@ -1,5 +1,6 @@
 FROM node:20-slim
 
+# force rebuild to ensure git is installed
 RUN apt-get update && apt-get install -y --no-install-recommends \
     git \
     && rm -rf /var/lib/apt/lists/*

TODO.md

@@ -29,5 +29,4 @@
 
 每個階段都會加上明確的 log，並確保即使部分功能未完成也能降級執行、不會中斷 pipeline。
 
-每次執行後請貼 log，我會協助 debug。
-
+每次執行後請貼 log，我會協助 debug。

app/git.js

@@ -1,19 +1,17 @@
 import { spawnSync } from 'child_process';
+import path from 'path';
 import { GITEA_SERVER_URL, GITEA_REPOSITORY, GITEA_TOKEN, PR_HEAD_BRANCH, FINDINGS_PATH } from './config.js';
 
 function git(args, cwd) {
   const result = spawnSync('git', args, { cwd, encoding: 'utf8' });
   if (result.error) throw result.error;
-  if (result.status !== 0) throw new Error(result.stderr || result.stdout);
+  if (result.status !== 0) throw new Error((result.stderr || result.stdout || '').trim());
   return (result.stdout || '').trim();
 }
 
-/**
- * Commit findings.json 並 push 到 PR 來源分支
- */
-export function commitAndPush(workspace) {
-  const repoDir = `${workspace}/${GITEA_REPOSITORY}`;
-  const remoteUrl = GITEA_SERVER_URL.replace(/\/$/, '').replace('https://', `https://${GITEA_TOKEN}@`) + `/${GITEA_REPOSITORY}.git`;
+export async function commitAndPush(workspace) {
+  const repoDir = path.join(workspace, GITEA_REPOSITORY);
+  const remoteUrl = GITEA_SERVER_URL.replace(/\/$/, '').replace('https://', `https://${GITEA_TOKEN}@`).replace('http://', `http://${GITEA_TOKEN}@`) + `/${GITEA_REPOSITORY}.git`;
 
   try {
     git(['config', 'user.email', 'ai-review[bot]@gitea'], repoDir);

app/main.js

@@ -91,7 +91,7 @@ async function main() {
 
   // Step5: commit/push findings.json 到來源分支
   console.log('\n💾 Step5: 記憶區 Commit/Push');
-  commitAndPush(WORKSPACE);
+  await commitAndPush(WORKSPACE);
 
   // Step6: 有 critical 問題則 exit 1
   console.log('\n🚦 Step6: 嚴重問題檢查');