feat: AI 审核自动驳回 + 功效词可配置 + UI 修复

- AI 自动驳回：法规/品牌安全 HIGH 违规或总分<40 自动打回上传阶段
- 功效词可配置：从硬编码改为品牌方在规则页面自行管理
- 驳回通知：AI 驳回时只通知达人，含具体原因
- 达人端：脚本/视频页面展示 AI 驳回原因 + 重新上传入口
- 规则页面：新增"功效词"分类
- 种子数据：新增 6 条默认功效词
- 其他：代理商管理下拉修复、AI 配置模型列表扩展、视觉模型标签修正、规则编辑放开限制

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

backend/app/services/task_service.py

@@ -195,6 +195,42 @@ async def upload_video(
     return task
 
 
+AI_AUTO_REJECT_SCORE = 40
+
+
+def _check_ai_auto_reject(score: int, result: dict) -> tuple[bool, str]:
+    """
+    判断 AI 审核结果是否应自动驳回
+
+    触发条件（任一）：
+    1. 法规合规维度存在 HIGH 级违规（违禁词/功效词）
+    2. 品牌安全维度存在 HIGH 级违规（竞品提及）
+    3. 总分 < 40
+    """
+    reasons = []
+    violations = result.get("violations", [])
+
+    # 条件1: 法规 HIGH
+    high_legal = [v for v in violations if v.get("dimension") == "legal" and v.get("severity") == "high"]
+    if high_legal:
+        words = [v.get("content", "") for v in high_legal[:5]]
+        reasons.append(f"法规违规：{', '.join(words)}")
+
+    # 条件2: 品牌安全 HIGH
+    high_brand = [v for v in violations if v.get("dimension") == "brand_safety" and v.get("severity") == "high"]
+    if high_brand:
+        words = [v.get("content", "") for v in high_brand[:5]]
+        reasons.append(f"品牌安全违规：{', '.join(words)}")
+
+    # 条件3: 总分过低
+    if score < AI_AUTO_REJECT_SCORE:
+        reasons.append(f"综合评分 {score} 分，低于合格线 {AI_AUTO_REJECT_SCORE} 分")
+
+    if reasons:
+        return True, "；".join(reasons)
+    return False, ""
+
+
 async def complete_ai_review(
     db: AsyncSession,
     task: Task,
@@ -206,9 +242,16 @@ async def complete_ai_review(
     完成 AI 审核
 
     - 更新 AI 审核结果
-    - 状态流转到代理商审核
+    - 自动驳回：法规/品牌安全 HIGH 违规或总分 < 40 → 回到上传阶段
+    - 正常：流转到代理商审核
     """
     now = datetime.now(timezone.utc)
+    auto_rejected, reject_reason = _check_ai_auto_reject(score, result)
+
+    # 将自动驳回信息写入 result，前端可据此展示
+    if auto_rejected:
+        result["ai_auto_rejected"] = True
+        result["ai_reject_reason"] = reject_reason
 
     if review_type == "script":
         if task.stage != TaskStage.SCRIPT_AI_REVIEW:
@@ -217,7 +260,11 @@ async def complete_ai_review(
         task.script_ai_score = score
         task.script_ai_result = result
         task.script_ai_reviewed_at = now
-        task.stage = TaskStage.SCRIPT_AGENCY_REVIEW
+
+        if auto_rejected:
+            task.stage = TaskStage.SCRIPT_UPLOAD
+        else:
+            task.stage = TaskStage.SCRIPT_AGENCY_REVIEW
 
     elif review_type == "video":
         if task.stage != TaskStage.VIDEO_AI_REVIEW:
@@ -226,7 +273,11 @@ async def complete_ai_review(
         task.video_ai_score = score
         task.video_ai_result = result
         task.video_ai_reviewed_at = now
-        task.stage = TaskStage.VIDEO_AGENCY_REVIEW
+
+        if auto_rejected:
+            task.stage = TaskStage.VIDEO_UPLOAD
+        else:
+            task.stage = TaskStage.VIDEO_AGENCY_REVIEW
 
     else:
         raise ValueError(f"不支持的审核类型: {review_type}")