feat(ui): structured editors for script schemas and alarm triggers

Replace raw-JSON text inputs with rich UI: script parameter/return types use
a JSON Schema builder (SchemaBuilder + JsonSchemaShapeParser, with a migration
to convert existing definitions); alarm trigger config uses a type-aware
editor with a flattened attribute picker (AlarmTriggerEditor). AlarmActor
gains optional direction (rising/falling/either) on RateOfChange triggers.

src/ScadaLink.CentralUI/Components/Shared/AlarmAttributeChoice.cs

@@ -0,0 +1,8 @@
+namespace ScadaLink.CentralUI.Components.Shared;
+
+/// <summary>
+/// One option in the alarm trigger editor's attribute picker.
+/// <see cref="Source"/> is one of "Direct", "Inherited", or "Composed" —
+/// used to group entries in the dropdown.
+/// </summary>
+public record AlarmAttributeChoice(string CanonicalName, string DataType, string Source);