fix(ci): pr_auto_scan修复崩溃bug + 统一merge门禁为CI Gate

- api_request: 修复HTTPError空响应体导致JSON解析崩溃
- REQUIRED_CONTEXTS_FULL: 改为只检查CI Gate，与pr-automation/分支保护保持一致
- FRONTEND_ONLY_CONTEXT: 改为CI Gate，内部自动处理跳过逻辑

scripts/ci/pr_auto_scan.py

@@ -32,7 +32,13 @@ def api_request(token, repo, endpoint, method="GET", data=None):
         resp = urllib.request.urlopen(req, context=ctx)
         return json.loads(resp.read().decode()), resp.status
     except urllib.error.HTTPError as e:
-        return json.loads(e.read().decode()) if e.read() else {"error": str(e)}, e.code
+        body = e.read().decode()
+        if body:
+            try:
+                return json.loads(body), e.code
+            except json.JSONDecodeError:
+                return {"error": body}, e.code
+        return {"error": str(e)}, e.code
 
 
 def get_open_prs(token, repo, base="develop"):
@@ -269,13 +275,9 @@ def main():
 
     # required contexts（与分支保护一致）
     REQUIRED_CONTEXTS_FULL = [
-        "CI/CD Pipeline / Validate - Code Quality (pull_request)",
-        "CI/CD Pipeline / Validate - Type Check (mypy) (pull_request)",
-        "CI/CD Pipeline / Validate - Migration (alembic) (pull_request)",
-        "CI/CD Pipeline / Frontend Lint (pull_request)",
-        "CI/CD Pipeline / PR Build API Image (pull_request)",
-        "CI/CD Pipeline / PR Build Worker Image (pull_request)",
-        "CI/CD Pipeline / PR Build Web Image (pull_request)",
+        # 统一使用CI Gate作为合并门禁（与pr-automation和分支保护保持一致）
+        # CI Gate内部已包含: 代码质量/类型检查/迁移检查/单测/集成测试/前端Lint/前端单测/构建/AI审查
+        "CI/CD Pipeline / CI Gate (pull_request)",
     ]
     REQUIRED_CONTEXTS_APPROVE = [
         "CI/CD Pipeline / Validate - Code Quality (pull_request)",
@@ -284,7 +286,8 @@ def main():
         "CI/CD Pipeline / Frontend Lint (pull_request)",
     ]
     FRONTEND_ONLY_CONTEXT = [
-        "CI/CD Pipeline / Frontend Lint (pull_request)",
+        # 纯前端PR也用CI Gate统一判断，内部自动跳过后端相关检查
+        "CI/CD Pipeline / CI Gate (pull_request)",
     ]
 
     # 获取所有open PR