feat(dcl): bound per-tag seed ReadAsync with SeedReadTimeout (#232, DCL-027)

src/ZB.MOM.WW.ScadaBridge.DataConnectionLayer/DataConnectionOptions.cs

@@ -14,6 +14,16 @@ public class DataConnectionOptions
     /// <summary>Timeout for synchronous write operations to devices.</summary>
     public TimeSpan WriteTimeout { get; set; } = TimeSpan.FromSeconds(30);
 
+    /// <summary>
+    /// DataConnectionLayer-027: per-tag timeout applied to each <see cref="IDataConnection.ReadAsync"/>
+    /// call on the initial-subscribe seed path (and reconnect re-seed). A hung device read would
+    /// otherwise delay <c>SubscribeCompleted</c> and its acknowledgement indefinitely. On timeout
+    /// the tag is treated the same as any other failed seed read — it stays in the pending set and
+    /// is retried up to <see cref="SeedReadMaxAttempts"/>, then left Uncertain until a change
+    /// notification arrives.
+    /// </summary>
+    public TimeSpan SeedReadTimeout { get; set; } = TimeSpan.FromSeconds(30);
+
     /// <summary>
     /// Minimum time a connection must stay up before it is considered stable.
     /// If a connection drops before this threshold, it counts as an unstable