fix: accelerate EM trajectories from rest

ClumsyPilot/tests/EMPlannerVerificationHost/EmPlanningServiceChecks.cs

@@ -19,6 +19,7 @@ internal static class EmPlanningServiceChecks
         VerifiesFullScopePublishesItsRequestScope();
         VerifiesRequestAndStateFailuresPublishNoTrajectory();
         VerifiesProjectionCorridorAndOptimizationFailuresPublishNoTrajectory();
+        VerifiesNoProgressPublishesNoTrajectory();
         VerifiesTimeoutFallbackAndCancellationSemantics();
         VerifiesPublicationFailureAndDebugIsolation();
     }
@@ -396,6 +397,22 @@ internal static class EmPlanningServiceChecks
         }
     }
 
+    private static void VerifiesNoProgressPublishesNoTrajectory()
+    {
+        EmPlanningRequest request = CreateRequest(TravelDirection.Forward, 0d, false, false,
+            CreateReferencePath(TravelDirection.Forward, false, 0.10d), null,
+            EmPlanningScope.FullDirectionSegment);
+        request.Configuration.Scheduling.MaximumOptimizationSpatialStepMeters = 1d;
+        request.Configuration.Scheduling.MaximumOptimizationTimeStepSeconds = 1d;
+
+        EmPlanningResult result = new EmPlanningService(new ScriptedPipelineSolver(PipelineSolverMode.NoProgress)).Plan(
+            request, CancellationToken.None);
+
+        VerifyFailure(result, EmPlanningStatus.NoProgress, "full nonterminal no progress");
+        Verification.True(result.FailureReason.IndexOf("NoProgress", StringComparison.Ordinal) >= 0,
+            "no-progress failure preserves its diagnostic");
+    }
+
     private static void VerifiesPublicationFailureAndDebugIsolation()
     {
         EmPlanningRequest validationFailure = CreateRequest(TravelDirection.Forward, 0d, false, false);
@@ -610,6 +627,7 @@ internal static class EmPlanningServiceChecks
         SolverUnavailable,
         TimeoutWithoutFallback,
         TimeoutWithFallback,
+        NoProgress,
         PublicationValidationFailure,
     }
 
@@ -647,6 +665,8 @@ internal static class EmPlanningServiceChecks
             LastLongitudinalProblem = problem;
             if (mode == PipelineSolverMode.LongitudinalInfeasible)
                 return Result(QpSolveStatus.PrimalInfeasible, Array.Empty<double>());
+            if (mode == PipelineSolverMode.NoProgress)
+                return Result(QpSolveStatus.Solved, new double[problem.VariableCount]);
             if (strictFullPrimal != null && strictFullPrimal.Count == problem.VariableCount)
             {
                 longitudinalCallCount++;