refactor: retire price_events.json completely — DB is the only store

User directive: no JSON, retire it fully, fix all related code.

Changes:
- price_monitor.py: record_event writes DB only; removed EVENTS_PATH/
  load_events/save_events entirely
- strategy_feedback.py: price events read from DB only (removed JSON fallback)
- system_health_check.py: removed price_events.json from file-check list,
  DB-only event stats (was showing 0/0 due to wrong-DB resolution)
- mo_config.py: removed dead price_events_path property (no callers)
- mofin_health.py: price_events freshness reads DB table (authoritative now)
- mofin_db.py: DATA_DIR/DB_PATH now ABSOLUTE (/home/hmo/MoFin/data) —
  was relative __file__.parent, so each hardlinked copy of mofin_db.py
  resolved to a DIFFERENT database (canonical vs web-dashboard vs
  profile-local third DB with 0 rows of everything except market_snapshots).
  This fragmentation was the real cause of health checks reading empty tables.
- Unified all 4 mofin_db copies (root/scripts/deploy/profile) via hardlink
- price_events.json archived to trashbox (fully backfilled: 6353 rows in DB)

Verified:
- record_event lands in DB only, JSON not recreated
- system_health_check: 历史事件 6353 / 今日事件 2965 (was 0/0)
- strategy_feedback + price_monitor full runs clean

deploy/profile-scripts/strategy_feedback.py

@@ -18,7 +18,6 @@ from mo_data import read_decisions
 
 DATA_DIR = Path(__file__).parent.parent / "data"
 ACCURACY_PATH = DATA_DIR / "accuracy_stats.json"
-EVENTS_PATH = DATA_DIR / "price_events.json"
 FEEDBACK_PATH = DATA_DIR / "strategy_feedback.json"
 
 
@@ -174,15 +173,16 @@ def generate_adjustment(decision, phase_check, accuracy_trend):
 
 def run():
     decisions = read_decisions()
-    # 优先从 SQLite 读取价格事件
+    # 价格事件：只从 DB price_events 表读（JSON 已退役）
     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": []})
+    except Exception as e:
+        print(f"[strategy_feedback] DB价格事件读取失败: {e}", file=sys.stderr)
+        events = {"events": []}
     accuracy_stats = load_json(ACCURACY_PATH, {})
 
     accuracy_trend = compute_accuracy_trend(accuracy_stats)