docs: gate Local G2 pipeline on stable region order

docs/superpowers/plans/2026-07-30-local-g2-path-presmoothing.md

@@ -1189,6 +1189,7 @@ git commit -m "feat: validate local G2 candidate quality"
 **Files:**
 
 - Create: `ClumsyPilot/ParkrobTrajplanner/PathSmoothing/LocalG2/LocalG2PreSmoothingPipeline.cs`
+- Consume unchanged: `ClumsyPilot/ParkrobTrajplanner/PathSmoothing/LocalG2/LocalG2RegionWorkOrder.cs`
 - Modify: `ClumsyPilot/ParkrobTrajplanner/PathSmoothing/Facade/PathSmoothingService.cs`
 - Create: `ClumsyPilot/tests/verify_path_smoothing_local_g2_integration.ps1`
 - Modify: `ClumsyPilot/tests/verify_path_smoothing_service.ps1`
@@ -1196,6 +1197,8 @@ git commit -m "feat: validate local G2 candidate quality"
 **Interfaces:**
 
 - Consumes: validated request, prepared path and fair raw baseline.
+- Consumes `LocalG2RegionWorkOrder.TryCreate(...)`; pipeline iteration must not use report-order regions directly.
+- Publishes region reports in the detector's original ascending order, independently of processing order.
 - Produces:
 
 ```csharp
@@ -1242,6 +1245,21 @@ Assert-True ($result.Diagnostics.Metrics.MinimumBodyClearanceMeters -ge 0.02) `
 
 For `Complete` and `PartialImprovement`, require at least one region report with `Improved`. For `PartialImprovement`, require at least one `RetainedOriginal`. Run every fixture twice and compare status, point count, coordinates and region reports.
 
+Create one deterministic same-direction fixture with two disjoint detected
+regions. Both accepted candidates must change their local replacement length.
+Assert:
+
+1. the larger-original-arc region is evaluated first;
+2. the second processed region still matches the intended original front
+   window endpoints;
+3. both reports are `Improved`;
+4. reports are published in ascending original arc order;
+5. both Local G2 replacements are present in the final full path;
+6. two identical requests produce equal status, candidate indices, report
+   order, point count and point coordinates.
+
+The test must fail if the pipeline replaces `workRegions` with `regions`.
+
 Also create two explicit service cases:
 
 ```powershell
@@ -1273,31 +1291,68 @@ Expected: fail because the service cannot resolve `LocalG2Quintic`.
 Pipeline pseudocode must be implemented directly:
 
 ```csharp
+if (!_workOrder.TryCreate(
+        regions,
+        out IReadOnlyList<LocalG2SmoothingRegion> workRegions,
+        out string orderReason))
+{
+    return PathSmoothingResult.Failure(
+        PathSmoothingStatus.Failed,
+        new PathSmoothingDiagnostics(
+            new PathQualityMetrics(),
+            TimeSpan.Zero,
+            0,
+            0d,
+            orderReason));
+}
+
 PreparedPath current = preparedPath;
-var reports = new List<PathSmoothingRegionReport>();
+var reportsByRegion = new Dictionary<LocalG2SmoothingRegion, PathSmoothingRegionReport>();
 int improvedCount = 0;
 
-foreach (LocalG2SmoothingRegion region in regions)
+foreach (LocalG2SmoothingRegion region in workRegions)
 {
     cancellationToken.ThrowIfCancellationRequested();
     IReadOnlyList<LocalG2CandidateGeometry> candidates =
-        _builder.Build(preparedPath.Segments[region.SegmentIndex], region, outputSpacing, options, cancellationToken);
+        _builder.Build(
+            preparedPath.Segments[region.SegmentIndex],
+            region,
+            outputSpacing,
+            options,
+            cancellationToken);
     var evaluations = new List<LocalG2CandidateEvaluation>();
     foreach (LocalG2CandidateGeometry candidate in candidates)
-        evaluations.Add(_evaluator.Evaluate(preparedPath, current, region, candidate, request, options, cancellationToken));
+    {
+        evaluations.Add(
+            _evaluator.Evaluate(
+                preparedPath,
+                current,
+                region,
+                candidate,
+                request,
+                options,
+                cancellationToken));
+    }
 
-    LocalG2CandidateEvaluation best = LocalG2CandidateEvaluator.SelectBest(evaluations);
+    LocalG2CandidateEvaluation best =
+        LocalG2CandidateEvaluator.SelectBest(evaluations);
     if (best != null && best.Accepted)
     {
         current = best.SplicedPreparedPath;
         improvedCount++;
-        reports.Add(CreateImprovedReport(region, best));
+        reportsByRegion.Add(region, CreateImprovedReport(region, best));
     }
     else
     {
-        reports.Add(CreateRetainedReport(region, evaluations));
+        reportsByRegion.Add(
+            region,
+            CreateRetainedReport(region, evaluations));
     }
 }
+
+var reports = new List<PathSmoothingRegionReport>(regions.Count);
+for (int reportIndex = 0; reportIndex < regions.Count; reportIndex++)
+    reports.Add(reportsByRegion[regions[reportIndex]]);
 ```
 
 Regions are disjoint after merging, so successful earlier replacements remain when a later region fails.