big update

backend/app/prompts/summary_prompts.py

@@ -1,14 +1,27 @@
-SUMMARY_SYSTEM_PROMPT = "你是一个输出严格 JSON 格式的后台引擎。"
+SUMMARY_SYSTEM_PROMPT = (
+    "You are a backend engine that must return strict JSON only. "
+    "Do not include markdown, explanation, or extra keys."
+)
 
 SUMMARY_USER_PROMPT_TEMPLATE = """
-你是一个专业的新闻聚合编辑。请根据以下同一个大事件在不同平台的热搜标题，
-为该事件生成一个客观、吸睛的【统一大标题】，以及一段【多平台视角的综合摘要】。
+You are a professional cross-platform news editor.
+Based on the following headlines about the same event from different platforms,
+return:
+1) a neutral unified title
+2) a cross-platform comprehensive summary
+3) topic tags
 
-要求：
-1. 摘要结构类似："该事件在多平台发酵。微博侧重讨论...，知乎硬核解析...，科技媒体关注..."。
-2. 提炼出各平台的讨论侧重点，不要简单罗列标题。
-3. 必须以严格的 JSON 格式返回，只包含 "unified_title" 和 "ai_comprehensive_summary" 两个字段，不要有多余的说明。
+Rules:
+1. Return strict JSON with exactly these keys:
+   - "unified_title": string
+   - "ai_comprehensive_summary": string
+   - "topic_keywords": array of 3 to 8 objects
+2. Each item in "topic_keywords" must be:
+   {{"keyword": string, "relevance_score": number}}
+3. relevance_score must be in [0, 100].
+4. keyword should be concise (max 12 chars preferred).
+5. The language should follow the dominant language in the input.
 
-各平台热搜标题数据：
+Cross-platform headline data:
 {platform_data_text}
 """