docs(galaxy): neutralize remaining stale SystemPlatform/alias terminology in comments + a test name

Replace "SystemPlatform mirror tag", "Galaxy alias", and "SystemPlatform-kind" in doc-comments and
test names with neutral accurate wording ("FolderPath-scoped tag", "EquipmentId == null", etc.).
No code, logic, or test bodies changed — comments and one test method name only.

src/Core/ZB.MOM.WW.OtOpcUa.Configuration/Entities/Tag.cs

@@ -31,8 +31,7 @@ public sealed class Tag
     public string? DeviceId { get; set; }
 
     /// <summary>
-    ///     Set when the tag belongs to an Equipment (driver tag OR Galaxy alias); NULL for
-    ///     SystemPlatform mirror tags.
+    ///     Set when the tag belongs to an Equipment; NULL for FolderPath-scoped (namespace-root) tags.
     /// </summary>
     public string? EquipmentId { get; set; }
 
@@ -41,7 +40,7 @@ public sealed class Tag
     /// </summary>
     public required string Name { get; set; }
 
-    /// <summary>Only used when <see cref="EquipmentId"/> is NULL (SystemPlatform namespace).</summary>
+    /// <summary>Only used when <see cref="EquipmentId"/> is NULL (FolderPath-scoped namespace tag).</summary>
     public string? FolderPath { get; set; }
 
     /// <summary>OPC UA built-in type name (Boolean / Int32 / Float / etc.).</summary>

src/Core/ZB.MOM.WW.OtOpcUa.Configuration/Enums/NodeAclScopeKind.cs

@@ -9,7 +9,7 @@ public enum NodeAclScopeKind
     UnsLine,
     Equipment,
     /// <summary>
-    ///     A Galaxy (SystemPlatform-kind) folder segment anchored below a namespace.
+    ///     A folder segment anchored below a namespace (used for FolderPath-scoped tags).
     ///     Distinguishes folder grants from UNS <see cref="Equipment"/> grants in the
     ///     <c>AuthorizationDecision.Provenance</c> audit trail and Admin UI diagnostics.
     /// </summary>

src/Core/ZB.MOM.WW.OtOpcUa.Core/OpcUa/EquipmentNodeWalker.cs

@@ -9,7 +9,7 @@ namespace ZB.MOM.WW.OtOpcUa.Core.OpcUa;
 ///     <see cref="Configuration.Entities.Namespace"/> from the Config DB's
 ///     <c>UnsArea</c> / <c>UnsLine</c> / <c>Equipment</c> / <c>Tag</c> rows. Runs during
 ///     address-space build per <see cref="IDriver"/> whose
-///     <c>Namespace.Kind = Equipment</c>; SystemPlatform-kind namespaces (Galaxy) are
+///     <c>Namespace.Kind = Equipment</c>; non-Equipment namespaces are
 ///     exempt per decision #120 and reach this walker only indirectly through
 ///     <see cref="ITagDiscovery.DiscoverAsync"/>.
 /// </summary>
@@ -21,7 +21,7 @@ namespace ZB.MOM.WW.OtOpcUa.Core.OpcUa;
 ///         folder node at the UNS level-5 segment; every <see cref="Tag"/> bound to an
 ///         Equipment (non-null <see cref="Tag.EquipmentId"/>) becomes a variable node under
 ///         it. Driver-discovered tags that have no Config-DB row are not added by this
-///         walker — the ITagDiscovery path continues to exist for the SystemPlatform case +
+///         walker — the ITagDiscovery path continues to exist for FolderPath-scoped tags +
 ///         for enrichment, but Equipment-kind composition is fully Tag-row-driven.
 ///     </para>
 ///