feat: Phase 2 新闻打分去重与 Agent 输入池裁剪

标题相似度合并、信源/时效/昨日重复加权排序，Agent 模式扩大 LLM 新闻候选池并记录抓取失败源。

Co-authored-by: Cursor <cursoragent@cursor.com>

daily/generate.py

@@ -49,6 +49,7 @@ from daily.news.fetch import (
     prepare_wecom_cn_news_items,
     prepare_wecom_news_items,
 )
+from daily.news.rank import apply_news_ranking
 from daily.report_data import (
     build_full_payload,
     build_llm_input,
@@ -439,6 +440,8 @@ def generate_report() -> tuple[str, str, Path, Path]:
     topic_name, github_topic = fetch_topic_hot_repos(topic_fetch_n, exclude=seen_repos)
     ai_news = fetch_ai_news()
     cn_ai_news = fetch_cn_ai_news()
+    ai_news = apply_news_ranking(ai_news, date_str=date_str)
+    cn_ai_news = apply_news_ranking(cn_ai_news, date_str=date_str)
 
     wecom_limits = {
         "trending": wecom_trending,
@@ -463,6 +466,7 @@ def generate_report() -> tuple[str, str, Path, Path]:
         ai_news=ai_news,
         cn_ai_news=cn_ai_news,
         wecom_limits=wecom_limits,
+        agent_mode=is_agent_mode(),
     )
     save_json(
         data_json_path(date_str),