ci: 新增 Gitea Actions workflow 讓 Claude 回應 issue/PR 事件

以 markwylde/claude-code-gitea-action 掛在 issue_comment、
pull_request_review_comment、issues、pull_request_review 事件上。
GITEA_SERVER_URL 覆寫為外部網址，避免容器內部 http://gitea:3000 連結外部無法存取。

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

.gitea/workflows/claude.yml

@@ -0,0 +1,26 @@
+name: Claude Assistant
+on:
+  issue_comment:
+    types: [created]
+  pull_request_review_comment:
+    types: [created]
+  issues:
+    types: [opened, assigned, labeled]
+  pull_request_review:
+    types: [submitted]
+
+jobs:
+  claude-response:
+    runs-on: yellow-zeabur-runner
+    steps:
+      - uses: actions/checkout@v4
+      - uses: markwylde/claude-code-gitea-action@v1.0.20
+        with:
+          anthropic_api_key: ${{ secrets.ANTHROPIC_API_KEY }}
+          gitea_token: ${{ secrets.USER_TOKEN }}
+          claude_git_name: Claude
+          claude_git_email: claude@anthropic.com
+        env:
+          # 如果 Gitea 跑在容器裡，內部連結會變成 http://gitea:3000，
+          # 用這個覆寫成外部可存取的網址
+          GITEA_SERVER_URL: https://yellow-git.zeabur.app