Match SSE ping comments to the 20s server heartbeat.

Rename the equals price-trigger condition to reach-this-price.

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

src/utils/priceSocket.ts

@@ -30,6 +30,7 @@ const ALERT_COOLDOWN_MS = 5 * 60 * 1000
 const FALLBACK_POLL_INTERVAL_MS = 10000
 const PRICE_SOURCE_STALE_MS_MOBILE = 50000
 const PRICE_SOURCE_STALE_MS_DESKTOP = 35000
+/** بدون event قیمت؛ ping هر ۲۰ث از سرور activity را تازه می‌کند */
 const STALE_STREAM_MS = 120000
 const FALLBACK_POLL_DELAY_MS = 2500
 const STREAM_CONNECTING = 0