Skip data timeout for shards with few subscriptions

Shards with < 50 subscriptions are exempt from data timeout since they
likely contain low-activity tokens that may not receive any updates
within the timeout window. This prevents constant false-positive
hot switchover loops on tail shards.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Author: KaboomFox

src/connection.rs

@@ -490,8 +490,9 @@ impl<H: WebSocketHandler> Connection<H> {
                         }
                     }
 
-                    // Check data timeout
-                    if health.is_data_timeout() {
+                    // Check data timeout (skip for shards with few subscriptions - they may have low-activity tokens)
+                    // Shards with < 50 subscriptions are exempt since inactive markets may not send data
+                    if health.is_data_timeout() && state.subscription_count >= 50 {
                         self.metrics.record_health_failure();
 
                         // Request hot switchover if channel available, otherwise regular reconnect