数据统计改为后台热缓存与 SSE，曲线放大置底并支持选机，对比增加模式与收益率。

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

app.py

@@ -63,7 +63,8 @@ from lib.instances_lib import (
 )
 from lib.overview_cache_lib import overview_store
 from lib.sso_lib import build_embed_open_url
-from lib.stats_agg_lib import build_stats_curve, build_stats_summary, normalize_window
+from lib.stats_agg_lib import normalize_window
+from lib.stats_cache_lib import stats_store
 from lib.wechat_lib import (
     hub_alert_cooldown_sec,
     hub_health_fail_threshold,
@@ -157,21 +158,43 @@ def stats_page():
 @app.route("/api/stats/summary")
 @login_required
 def api_stats_summary():
+    """只读统计热缓存;后台常驻刷新各窗口."""
     window = normalize_window(request.args.get("window") or "7d")
-    try:
-        return jsonify(build_stats_summary(window))
-    except Exception as e:
-        return jsonify({"ok": False, "msg": str(e) or "统计失败"}), 500
+    force = (request.args.get("force") or "").strip().lower() in ("1", "true", "yes")
+    if force:
+        stats_store.request_refresh()
+    return jsonify(stats_store.summary_dict(window))
 
 
 @app.route("/api/stats/curve")
 @login_required
 def api_stats_curve():
     range_key = normalize_window(request.args.get("range") or request.args.get("window") or "7d")
-    try:
-        return jsonify(build_stats_curve(range_key))
-    except Exception as e:
-        return jsonify({"ok": False, "msg": str(e) or "曲线失败"}), 500
+    force = (request.args.get("force") or "").strip().lower() in ("1", "true", "yes")
+    if force:
+        stats_store.request_refresh()
+    return jsonify(stats_store.curve_dict(range_key))
+
+
+@app.route("/api/stats/refresh", methods=["POST"])
+@login_required
+def api_stats_refresh():
+    stats_store.request_refresh()
+    return jsonify({"ok": True, "msg": "已触发统计后台刷新"})
+
+
+@app.route("/api/stats/stream")
+@login_required
+def api_stats_stream():
+    return Response(
+        stream_with_context(stats_store.iter_sse()),
+        mimetype="text/event-stream",
+        headers={
+            "Cache-Control": "no-cache",
+            "Connection": "keep-alive",
+            "X-Accel-Buffering": "no",
+        },
+    )
 
 
 @app.route("/instances", methods=["GET", "POST"])
@@ -533,7 +556,12 @@ def start_overview_cache() -> None:
     overview_store.start(pull_all_enabled, on_pull=_on_overview_pulled)
 
 
+def start_stats_cache() -> None:
+    stats_store.start()
+
+
 start_overview_cache()
+start_stats_cache()
 
 try:
     start_hub_backup_scheduler(