feat: 阶段1 — market_watch 双写 SQLite + 查询工具

- market_watch.py: 新增 init_db() 建表 + write_snapshot() 双写 SQLite
  - market_snapshots: 每次采集的元信息（时间、来源、涨跌比、情绪）
  - sector_snapshots: 每个板块的涨跌幅、资金流向、领涨股等
  - JSON 写入保留不变，SQLite 写入失败不影响 JSON 管道
- mofin_query.py: 通用查询工具
  - 板块趋势查询：「半导体最近5次采集的涨跌幅」
  - 资金流向排行：「净流入最多的5个板块」
  - 连续净流入检测：「最近3天连续净流入的板块」
  - 市场情绪趋势 + 数据库概览
  - 支持直接 SQL 查询

market_watch.py

@@ -13,10 +13,102 @@
 """
 
 import json
+import sqlite3
 from datetime import datetime
 from pathlib import Path
 
 DATA_DIR = Path(__file__).parent / "data"
+DB_PATH = DATA_DIR / "mofin.db"
+
+# ── 数据库初始化 ──────────────────────────────────────
+
+def init_db():
+    """创建 mofin.db 及所有表（幂等，已存在则跳过）"""
+    DATA_DIR.mkdir(parents=True, exist_ok=True)
+    conn = sqlite3.connect(str(DB_PATH))
+    conn.execute("PRAGMA journal_mode=WAL")
+    conn.execute("PRAGMA foreign_keys=ON")
+    conn.executescript("""
+        CREATE TABLE IF NOT EXISTS market_snapshots (
+            id          INTEGER PRIMARY KEY AUTOINCREMENT,
+            timestamp   TEXT    NOT NULL,
+            source      TEXT    NOT NULL DEFAULT 'ths',
+            up_ratio    REAL,
+            mood        TEXT,
+            created_at  TEXT    DEFAULT (datetime('now','localtime'))
+        );
+        CREATE INDEX IF NOT EXISTS idx_snapshots_time ON market_snapshots(timestamp);
+
+        CREATE TABLE IF NOT EXISTS sector_snapshots (
+            id              INTEGER PRIMARY KEY AUTOINCREMENT,
+            snapshot_id     INTEGER NOT NULL REFERENCES market_snapshots(id),
+            name            TEXT    NOT NULL,
+            change_pct      REAL,
+            up_count        INTEGER,
+            down_count      INTEGER,
+            net_inflow      REAL,
+            lead_stock      TEXT,
+            lead_stock_change REAL,
+            volume          REAL,
+            turnover        REAL
+        );
+        CREATE INDEX IF NOT EXISTS idx_sector_name ON sector_snapshots(name);
+        CREATE INDEX IF NOT EXISTS idx_sector_snapshot ON sector_snapshots(snapshot_id);
+        CREATE INDEX IF NOT EXISTS idx_sector_name_time ON sector_snapshots(name, snapshot_id);
+    """)
+    conn.commit()
+    return conn
+
+
+def write_snapshot(conn, market_data: dict):
+    """将一次采集结果双写 SQLite（JSON 写入由 main 负责）"""
+    try:
+        # 1. INSERT market_snapshots
+        cur = conn.execute(
+            """INSERT INTO market_snapshots (timestamp, source, up_ratio, mood)
+               VALUES (?, ?, ?, ?)""",
+            (
+                market_data["timestamp"],
+                market_data.get("source", "unknown"),
+                market_data.get("up_ratio", 0),
+                market_data.get("mood", "unknown"),
+            ),
+        )
+        snapshot_id = cur.lastrowid
+
+        # 2. INSERT sector_snapshots（逐板块）
+        sectors = market_data.get("sectors", [])
+        rows = []
+        for s in sectors:
+            rows.append((
+                snapshot_id,
+                s.get("name", ""),
+                s.get("change", 0),
+                s.get("up_count"),
+                s.get("down_count"),
+                s.get("net_inflow"),
+                s.get("lead_stock"),
+                s.get("lead_stock_change"),
+                s.get("volume"),
+                s.get("turnover"),
+            ))
+        if rows:
+            conn.executemany(
+                """INSERT INTO sector_snapshots
+                   (snapshot_id, name, change_pct, up_count, down_count,
+                    net_inflow, lead_stock, lead_stock_change, volume, turnover)
+                   VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?)""",
+                rows,
+            )
+        conn.commit()
+        return snapshot_id, len(rows)
+    except Exception as e:
+        print(f"[DB] SQLite 写入失败（JSON 不受影响）: {e}", flush=True)
+        try:
+            conn.rollback()
+        except Exception:
+            pass
+        return None, 0
 
 
 # ── 後端A：東方財富 push2 API（首選，有板塊代碼+實時指數） ──
@@ -159,6 +251,13 @@ def main():
     with open(DATA_DIR / "market.json", "w", encoding="utf-8") as f:
         json.dump(market_data, f, ensure_ascii=False, indent=2)
 
+    # ── SQLite 双写 ──
+    conn = init_db()
+    sid, count = write_snapshot(conn, market_data)
+    if sid:
+        print(f"[DB] snapshot_id={sid}, sectors={count}", flush=True)
+    conn.close()
+
     # 靜默：只寫文件，不輸出到stdout，避免cron推送