feat(sql): register Sql factory + probe in Host, add DriverTypeNames.Sql

Add DriverTypeNames.Sql (+ All) as the shared source of truth, and wire the driver
into the Host: register the factory in DriverFactoryBootstrap.Register via
Driver.Sql.SqlDriverFactoryExtensions.Register(registry, loggerFactory), add the
SqlProbe (= Driver.Sql.SqlDriverProbe) probe via TryAddEnumerable, and add the
Driver.Sql project reference to the Host. Default tier A (SQL client is managed +
cross-platform, so ShouldStub needs no change).

Repoint the interim SqlDriver.DriverTypeName / SqlDriverFactoryExtensions.DriverTypeName
literals at DriverTypeNames.Sql; both still resolve to "Sql", so the AdminUI
TagConfigEditorMap/TagConfigValidator keys and the DriverTypeName-parity test stay
green. The Core guard test discovers factories from its own bin, so it also gains a
Driver.Sql project reference — that is the "registered-factory side" that lets
DriverTypeNamesGuardTests' bidirectional-parity check pass (4/4 green).

Claude-Session: https://claude.ai/code/session_01GASWkNEi68FSCtvr6rLoEW

src/Core/ZB.MOM.WW.OtOpcUa.Core.Abstractions/DriverTypeNames.cs

@@ -53,6 +53,9 @@ public static class DriverTypeNames
     /// <summary>Calculation pseudo-driver — tags computed by C# scripts over other tags' live values.</summary>
     public const string Calculation = "Calculation";
 
+    /// <summary>Read-only SQL Server table/view poller — publishes columns as OPC UA variables.</summary>
+    public const string Sql = "Sql";
+
     /// <summary>
     ///     Every driver-type string declared above, for callers that need to enumerate
     ///     the full set (e.g. validation of an authored <c>DriverType</c>).
@@ -68,5 +71,6 @@ public static class DriverTypeNames
         OpcUaClient,
         Galaxy,
         Calculation,
+        Sql,
     ];
 }