fix: 四所统计日历 embed 切换后初始化与加载失败仍渲染网格

统一 initInstanceStatsCalendar，统计 tab 动态注入时重新挂载日历，API 异常时保留月历骨架。

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

static/trade_stats_calendar.js

@@ -71,7 +71,7 @@
 
   TradeStatsCalendar.prototype.render = function () {
     if (!this.gridEl || !this.titleEl) return;
-    this.ensureMonth(new Date());
+    if (this.year <= 0 || this.month <= 0) this.ensureMonth(new Date());
     this.titleEl.textContent = monthLabel(this.year, this.month);
     var first = new Date(this.year, this.month - 1, 1);
     var lastDay = new Date(this.year, this.month, 0).getDate();
@@ -149,6 +149,7 @@
 
   TradeStatsCalendar.prototype.load = async function () {
     this.ensureMonth(new Date());
+    this.render();
     var q = this.buildQuery(this.year, this.month);
     if (!q.has("year")) q.set("year", String(this.year));
     if (!q.has("month")) q.set("month", String(this.month));
@@ -160,6 +161,10 @@
         var resp = await fetch(this.apiUrl + "?" + q.toString(), {
           credentials: "same-origin",
         });
+        if (!resp.ok) {
+          console.warn("[trade calendar] api", resp.status);
+          return;
+        }
         data = await resp.json();
       }
       this.days = this.parseResponse(data) || {};
@@ -167,6 +172,7 @@
       if (this.onMonthChange) this.onMonthChange(this.year, this.month, this.days);
     } catch (e) {
       console.warn("[trade calendar]", e);
+      this.render();
     }
   };
 
@@ -200,4 +206,36 @@
   };
 
   global.TradeStatsCalendar = TradeStatsCalendar;
+
+  global.statsCalendarWidget = null;
+
+  global.initInstanceStatsCalendar = function () {
+    var grid = document.getElementById("stats-calendar");
+    if (!grid || !global.TradeStatsCalendar) return null;
+    global.statsCalendarWidget = new TradeStatsCalendar({
+      gridEl: grid,
+      titleEl: document.getElementById("stats-cal-title"),
+      prevBtn: document.getElementById("stats-cal-prev"),
+      nextBtn: document.getElementById("stats-cal-next"),
+      apiUrl: "/api/stats/calendar",
+      showSick: false,
+      buildQuery: function (year, month) {
+        var q = new URLSearchParams();
+        q.set("year", String(year));
+        q.set("month", String(month));
+        var sel = document.getElementById("stats-segment-select");
+        if (sel) q.set("segment", sel.value || "all");
+        return q;
+      },
+      parseResponse: function (data) {
+        if (data && data.ok === false) return {};
+        return (data && data.days) || {};
+      },
+    });
+    global.statsCalendarWidget.render();
+    void global.statsCalendarWidget.load();
+    return global.statsCalendarWidget;
+  };
+
+  global.initStatsCalendarWidget = global.initInstanceStatsCalendar;
 })(window);