feat(dcl+ui): rename BrowseOpcUaNode -> ConnectionName-keyed; implement site handler + dialog failure mapping

- BrowseOpcUaNodeCommand: int DataConnectionId -> string ConnectionName
  (site DataConnectionManagerActor indexes children by name; CentralUI
  already has the connection name in scope via the dropdown — no extra
  plumbing across the trust boundary).
- IOpcUaBrowseService / OpcUaBrowseService: parameter renamed accordingly.
- OpcUaBrowserDialog: collapse the duplicate ConnectionName parameters
  (display label and routing key are the same string).
- Task 10: DataConnectionManagerActor forwards BrowseOpcUaNodeCommand to
  its child by name (owns ConnectionNotFound); DataConnectionActor adds
  the receive across all three lifecycle states (Connecting / Connected
  / Reconnecting) and maps adapter outcomes to BrowseFailureKind
  (NotBrowsable / ConnectionNotConnected / Timeout / ServerError).
- Task 17: SetFailure in OpcUaBrowserDialog implements the full
  BrowseFailureKind switch with friendly UI messages.
- Tests: DataConnectionManagerBrowseHandlerTests covers ConnectionNotFound,
  NotBrowsable, success, and ConnectionNotConnectedException paths.

src/ZB.MOM.WW.ScadaBridge.Commons/Messages/Management/BrowseCommands.cs

@@ -6,10 +6,17 @@ namespace ZB.MOM.WW.ScadaBridge.Commons.Messages.Management;
 /// Sent from CentralUI to a specific site to enumerate the immediate children
 /// of an OPC UA node on the live server backing the given data connection.
 /// </summary>
-/// <param name="DataConnectionId">Id of the site-local data connection to browse against.</param>
+/// <remarks>
+/// Keyed by <see cref="ConnectionName"/> (not id) because the site-side
+/// <c>DataConnectionManagerActor</c> indexes its children by connection name —
+/// the central UI already has the connection name in scope (dropdown), so a
+/// string carries no extra plumbing across the trust boundary. The central
+/// <c>DataConnections</c> table's id is intentionally not exposed at the site.
+/// </remarks>
+/// <param name="ConnectionName">Name of the site-local data connection to browse against.</param>
 /// <param name="ParentNodeId">Node to browse, or null to browse from the server root (ObjectsFolder).</param>
 public record BrowseOpcUaNodeCommand(
-    int DataConnectionId,
+    string ConnectionName,
     string? ParentNodeId);
 
 public record BrowseOpcUaNodeResult(