refactor: 消费者切 SQLite 优先读取

切换策略: SQLite 优先 → 失败回退 JSON

price_events (100%覆盖):
- strategy_feedback.py: run() 优先 query_price_events()
- system_health_check.py: 优先 query_price_events() + query_price_events_by_date()

stock_sector_map (100%覆盖):
- strategy_lifecycle.py: load_stock_sector_map() 优先 stock_sectors 表

market.json (85%覆盖):
- strategy_lifecycle.py: load_market_context() 优先 query_latest_market()
- market_insight.py: generate() 优先 query_latest_market()

portfolio.json + watchlist.json (70%覆盖):
- strategy_lifecycle.py: regenerate_all() 优先 query_holdings() + query_watchlist()
- server.py: /api/portfolio, /api/watchlist, /api/overview, /api/market 优先 SQLite

所有改动保留 JSON 回退路径，SQLite 不可用时自动降级

strategy_feedback.py

@@ -175,7 +175,15 @@ def generate_adjustment(decision, phase_check, accuracy_trend):
 
 def run():
     decisions = load_json(DECISIONS_PATH, {"decisions": []})
-    events = load_json(EVENTS_PATH, {"events": []})
+    # 优先从 SQLite 读取价格事件
+    try:
+        from mofin_db import get_conn, query_price_events
+        conn = get_conn()
+        pe_rows = query_price_events(conn, limit=50000)
+        conn.close()
+        events = {"events": pe_rows}
+    except Exception:
+        events = load_json(EVENTS_PATH, {"events": []})
     accuracy_stats = load_json(ACCURACY_PATH, {})
 
     accuracy_trend = compute_accuracy_trend(accuracy_stats)