fix(crypto-tail): 监控分时图推送节流与前端采样，避免1s内多条数据导致点过密

- 后端: price_change 推送节流，每策略 1s 内最多推送 1 次，其余靠定时 1.5s 推送补足
- 前端: 同周期内分时图追加点时至少间隔 1s 才追加，保证曲线连续且不过密
- 最新价等展示仍实时更新，仅图表序列做采样

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

backend/src/main/kotlin/com/wrbug/polymarketbot/service/cryptotail/CryptoTailMonitorService.kt

@@ -97,6 +97,10 @@ class CryptoTailMonitorService(
     private val strategyHistoryPeriod = ConcurrentHashMap<Long, Long>()
     private val maxHistorySize = 300
 
+    /** price_change 推送节流：每策略最近一次推送时间，1s 内不重复推送 */
+    private val lastPriceChangePushTime = ConcurrentHashMap<Long, Long>()
+    private val priceChangePushThrottleMs = 1_000L
+
     data class MonitorEntry(
         val strategyId: Long,
         val strategy: CryptoTailStrategy,
@@ -652,8 +656,13 @@ class CryptoTailMonitorService(
 
             strategyPriceData[strategy.id!!] = newPriceData
 
-            val pushData = buildPushData(strategy, newPriceData)
-            addToHistoryAndPush(strategy.id!!, pushData)
+            val now = System.currentTimeMillis()
+            val last = lastPriceChangePushTime[strategy.id!!] ?: 0L
+            if (now - last >= priceChangePushThrottleMs) {
+                lastPriceChangePushTime[strategy.id!!] = now
+                val pushData = buildPushData(strategy, newPriceData)
+                addToHistoryAndPush(strategy.id!!, pushData)
+            }
         }
     }
 

frontend/src/pages/CryptoTailMonitor.tsx

@@ -159,15 +159,19 @@ const CryptoTailMonitor: React.FC = () => {
       setInitData(prev => prev ? { ...prev, periodStartUnix: pushPeriod } : null)
       setPriceHistory([newPoint])
     } else {
-      // 同周期：追加数据
-      // 记录首次数据时间（仅在中途进入且未切换过周期时记录）
+      // 同周期：追加数据（同周期内至少间隔 1s 才追加一点，避免 1s 内多条推送导致点过密）
       setFirstDataTime(prev => {
         if (prev == null) {
           return newPoint.time
         }
         return prev
       })
+      const minIntervalMs = 1_000
       setPriceHistory(prev => {
+        const lastTime = prev.length > 0 ? prev[prev.length - 1].time : 0
+        if (prev.length > 0 && newPoint.time - lastTime < minIntervalMs) {
+          return prev
+        }
         const maxPoints = 300
         const newHistory = [...prev, newPoint]
         return newHistory.slice(-maxPoints)