fix(web): 小周期切换时对齐标记，避免 LWC Value is null

主周期笔/KLC 分型标记在切到 1m/2m 主图时未对齐 K 线 time；过滤均线无效点并钳制视窗恢复。顺带统一 BI 中枢计算路径。

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

web/static/js/app/chart_sync.js

@@ -87,6 +87,21 @@ function updateTradingViewData() {
             });
         }
 
+        // LWC 不允许 null/NaN；时间用整秒，避免 Line 渲染抛 Value is null
+        candles = (candles || []).filter(function (c) {
+            return c && c.time != null &&
+                isFinite(Number(c.open)) && isFinite(Number(c.high)) &&
+                isFinite(Number(c.low)) && isFinite(Number(c.close));
+        }).map(function (c) {
+            return {
+                time: Math.floor(Number(c.time)),
+                open: Number(c.open),
+                high: Number(c.high),
+                low: Number(c.low),
+                close: Number(c.close)
+            };
+        });
+
         const newBarCount = candles.length;
         const barDelta = (oldBarCount > 0 && newBarCount > 0) ? (newBarCount - oldBarCount) : 0;
         
@@ -306,14 +321,28 @@ function updateTradingViewData() {
 
             const applyPosition = function (tag) {
                 let ok = false;
-                if (lr && lr.from !== undefined && lr.to !== undefined) {
+                if (lr && lr.from !== undefined && lr.to !== undefined && newBarCount > 0) {
+                    // 视窗超出当前 K 线数量时，LWC Line 绘制会抛 Value is null
+                    const span = Math.max(1, lr.to - lr.from);
+                    let to = lr.to;
+                    let from = lr.from;
+                    const maxTo = newBarCount - 1 + 8;
+                    if (to > maxTo) {
+                        to = maxTo;
+                        from = to - span;
+                    }
+                    if (from < -8) {
+                        from = -8;
+                        to = from + span;
+                    }
+                    const clamped = { from: from, to: to };
                     charts.forEach(c => {
                         try {
-                            c.timeScale().setVisibleLogicalRange({ from: lr.from, to: lr.to });
+                            c.timeScale().setVisibleLogicalRange(clamped);
                             ok = true;
                         } catch (e) {}
                     });
-                    if (ok) console.log('🔄 恢复位置 logical' + (tag || '') + ':', lr);
+                    if (ok) console.log('🔄 恢复位置 logical' + (tag || '') + ':', clamped);
                 }
                 if (!ok && vr && vr.from !== undefined && vr.to !== undefined) {
                     charts.forEach(c => {