fix: retain prepared Ortho context for script PXP-OA

Plant3D2026/P_Rec_Annot/src/PRecAnnot.Plant3D2026/ScriptDrivenFirstApplyAutomation.cs

@@ -6,6 +6,7 @@ using Autodesk.AutoCAD.DatabaseServices;
 using Autodesk.AutoCAD.Runtime;
 using Autodesk.ProcessPower.PlantInstance;
 using Autodesk.ProcessPower.ProjectManager;
+using PRecAnnot.Abstractions;
 using AcadApplication = Autodesk.AutoCAD.ApplicationServices.Application;
 
 namespace PRecAnnot.Plant3D2026;
@@ -26,6 +27,11 @@ internal static class ScriptDrivenFirstApplyAutomation
     private static readonly List<AutomationSentinelEvidence> sentinels = [];
     private static readonly List<AutomationCommandCorrelationEvidence> correlations = [];
     private static PxpOaDiscoveryEvidence? discovery;
+    // Plant's implicit current-document lookup can lag between script commands.
+    // PREPARE has already proved this immutable context belongs to the live fixture;
+    // retain it for the two immediately following public PXP-OA commands only.
+    private static PlantRuntimeContext? preparedContext;
+    private static string? selectedTargetSnapshotId;
     private static bool prepared;
     private static bool terminal;
 
@@ -53,6 +59,12 @@ internal static class ScriptDrivenFirstApplyAutomation
             var context = new PlantRuntimeContextReader().ReadCurrentContext(fixture);
             if (!context.HasPlantProject || !context.IsOrthoDrawing || context.Viewports.Count != 1)
                 throw new InvalidOperationException("AUTOMATION_ORTHO_CONTEXT_INVALID");
+            var candidates = new PlantObjectReader().ReadObjects(context.Viewports.Single(), CancellationToken.None)
+                .Where(x => string.Equals(x.ObjectClass, "Pipe", StringComparison.OrdinalIgnoreCase) && x.MembershipStatus == ViewMembershipStatus.Resolved && x.Geometry.PaperPosition is not null)
+                .Select(x => x.SnapshotId).OrderBy(x => x, StringComparer.Ordinal).ToArray();
+            if (candidates.Length == 0) throw new InvalidOperationException("AUTOMATION_NO_ELIGIBLE_CANDIDATE");
+            preparedContext = context;
+            selectedTargetSnapshotId = candidates[0];
             dbmodBaseline = Dbmod();
             baseline = Counts(database);
             prepared = true;
@@ -81,6 +93,18 @@ internal static class ScriptDrivenFirstApplyAutomation
         runs[^1] = last with { PlanId = planId, Candidates = candidates, View = view, Create = create, Skip = skip, SourceRows = sourceRows, MembershipResolved = membershipResolved };
     }
 
+    internal static bool TryGetPreparedContext(Document? commandDocument, out PlantRuntimeContext context)
+    {
+        context = null!;
+        if (!prepared || terminal || fixture is null || preparedContext is null || commandDocument is null || config is null) return false;
+        if (!SamePath(commandDocument.Name, config.OrthoDrawingPath) || !SamePath(fixture.Name, config.OrthoDrawingPath)) return false;
+        if (commandDocument.Database is null || database is null || !SamePath(commandDocument.Database.Filename, database.Filename)) return false;
+        context = preparedContext;
+        return true;
+    }
+
+    internal static string? SelectedTargetSnapshotId => prepared && !terminal ? selectedTargetSnapshotId : null;
+
     internal static void FinalizePreview()
     {
         try
@@ -149,7 +173,12 @@ internal static class ScriptDrivenFirstApplyAutomation
     }
     private static void Guard(Action action) { try { if (!terminal) action(); } catch (System.Exception ex) { Fail("AUTOMATION_EVENT_HANDLER_FAILED", ex); } }
     private static void Fail(string code, System.Exception exception) { if (terminal) return; terminal = true; transitions.Add("Failed:" + code); try { Write(false, code + ":" + exception); } finally { Unsubscribe(); } }
-    private static void Unsubscribe() { if (fixture is null) return; try { fixture.CommandWillStart -= OnWillStart; fixture.CommandEnded -= OnEnded; fixture.CommandFailed -= OnFailed; fixture.CommandCancelled -= OnCancelled; } catch { } }
+    private static void Unsubscribe()
+    {
+        if (fixture is not null) try { fixture.CommandWillStart -= OnWillStart; fixture.CommandEnded -= OnEnded; fixture.CommandFailed -= OnFailed; fixture.CommandCancelled -= OnCancelled; } catch { }
+        preparedContext = null;
+        selectedTargetSnapshotId = null;
+    }
     private static int? Dbmod() { try { return Convert.ToInt32(AcadApplication.GetSystemVariable("DBMOD")); } catch { return null; } }
     private static AutomationEntityCounts Counts(Database db)
     {