新增实例数据统计页：复盘 KPI 上、资金曲线下，系统设置可关。

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

lib/instance/instance_data_stats_register.py

@@ -0,0 +1,49 @@
+"""实例数据统计:复盘 KPI + 资金曲线 API,以及后台现金采样."""
+from __future__ import annotations
+
+from typing import Any, Callable
+
+from flask import Flask, jsonify, request
+
+
+def install_instance_data_stats(app: Flask, app_module: Any) -> None:
+    get_db: Callable = app_module.get_db
+    login_required = app_module.login_required
+
+    def _fetch_balances() -> dict[str, Any]:
+        ex = getattr(app_module, "exchange_options", None)
+        if ex is None:
+            return {}
+        from lib.exchange.okx_options_lib import fetch_options_balances
+
+        return fetch_options_balances(ex, force=False) or {}
+
+    @app.route("/api/instance/cash_curve")
+    @login_required
+    def api_instance_cash_curve():
+        from lib.instance.instance_cash_sample_lib import (
+            query_cash_series_with_db,
+            sample_once,
+        )
+
+        # 打开页面时尽量补一笔最新点(失败忽略)
+        try:
+            sample_once(get_db, _fetch_balances)
+        except Exception:
+            pass
+        range_key = (request.args.get("range") or "7d").strip()
+        conn = get_db()
+        try:
+            return jsonify(query_cash_series_with_db(conn, range_key=range_key))
+        except Exception as e:
+            return jsonify({"ok": False, "msg": f"加载资金曲线失败: {e}"}), 500
+        finally:
+            conn.close()
+
+    # 后台采样(daemon);无密钥时会空转跳过
+    try:
+        from lib.instance.instance_cash_sample_lib import start_cash_sample_loop
+
+        start_cash_sample_loop(get_db, _fetch_balances)
+    except Exception as e:
+        print(f"[instance_cash_sample] start skipped: {e}", flush=True)