fix(lmxproxy): reset probe timer after reconnect to prevent false stale triggers

Without this, the staleness check could fire immediately after reconnect
before the first OnDataChange callback arrives, causing a reconnect loop.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

lmxproxy/src/ZB.MOM.WW.LmxProxy.Host/MxAccess/MxAccessClient.Connection.cs

@@ -243,6 +243,9 @@ namespace ZB.MOM.WW.LmxProxy.Host.MxAccess
                 if (!IsConnected)
                 {
                     await AttemptReconnectAsync(ct);
+                    // Reset probe timer so the next check gives the new connection
+                    // a full interval to deliver its first OnDataChange callback
+                    _lastProbeValueTime = DateTime.UtcNow;
                     continue;
                 }
 
@@ -267,6 +270,7 @@ namespace ZB.MOM.WW.LmxProxy.Host.MxAccess
                     }
 
                     await AttemptReconnectAsync(ct);
+                    _lastProbeValueTime = DateTime.UtcNow;
                 }
             }