feat: expose limited Apply preview candidates

Plant3D2026/P_Rec_Annot/src/PRecAnnot.Plant3D2026/EntryPoint.cs

@@ -100,6 +100,18 @@ public sealed class EntryPoint : IExtensionApplication
                 }));
             }
 
+            if (mode == PRecAnnotExecutionMode.DryRun &&
+                string.Equals(Environment.GetEnvironmentVariable("P_REC_ANNOT_DIAGNOSTICS"), "FirstLimitedApply", StringComparison.Ordinal))
+            {
+                var candidates = objectsByViewport.SelectMany(x => x)
+                    .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();
+                WriteEditor(document, $"\nP_Rec_Annot Apply preview candidates: {string.Join(",", candidates)}");
+                details["ApplyPreviewCandidateCount"] = candidates.Length;
+            }
+
             var summary = new
             {
                 ObjectsExamined = plans.Sum(x => x.Summary.ObjectsExamined),