feat: 记录并展示每次生成消耗的LLM调用次数（llm_calls）

backend/routes/admin.py

@@ -144,7 +144,7 @@ async def admin_list_reports(request: Request):
     try:
         rows = conn.execute(
             "SELECT id, trade_date, report_type, title, summary, tools_used, model, tokens_used, "
-            "generation_count, created_at, updated_at "
+            "generation_count, llm_calls, created_at, updated_at "
             "FROM ai_reports ORDER BY trade_date DESC, id DESC LIMIT 50"
         ).fetchall()
         items = []

backend/routes/ai_analysis.py

@@ -64,7 +64,7 @@ async def list_reports():
     try:
         rows = conn.execute(
             "SELECT id, trade_date, report_type, title, summary, tools_used, model, tokens_used, "
-            "generation_count, created_at, updated_at "
+            "generation_count, llm_calls, created_at, updated_at "
             "FROM ai_reports ORDER BY trade_date DESC, id DESC LIMIT 50"
         ).fetchall()
         items = []