streaming: far LODs keep a share while near work is pending (L79); no more horizon starvation

L78's strict near-first order starved far LODs at 30 m/s (100% far holes, never completed).
Unreal policy 2: once the collision ring is ready, LOD0-2 keep their reserve and far tiles are
admitted as low-priority Horizon work; headless gives far work 1 of every 16 requests.
Moving camera, far holes while moving: 1.4 m/s L77 8% / L78 29% / L79 31%; 30 m/s L77 8% /
L78 100% / L79 72% (completes on dwell). Near readiness while moving at 30 m/s: 52 / 51 / 67%.
Still worse than L77 for fast travel -> speed-adaptive policy next. World unchanged (v213).
Fast tier PASS; Linux UE host builds.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_016dhxM43dnWvUu2B5Ph1iG1

Standalone/Source/StreamBenchmarkHeadless.cpp

@@ -86,6 +86,11 @@ namespace
         bool HasCameraStep=false;
         bool AutoSurfaceCamera=false;
         bool CaptureSkipWalkability=false;
+        int StreamingSchedulerPolicy=-1;
+        bool MovingCameraTrace=false;
+        double MovingCameraSpeedMetersPerSecond=0.0;
+        double MovingCameraDurationSeconds=12.0;
+        double MovingCameraDwellSeconds=5.0;
         FVector CameraMeters=FVector::ZeroVector;
         FVector CameraStepMeters=FVector::ZeroVector;
         float CameraYawDegrees=0.0f;
@@ -1409,6 +1414,8 @@ namespace
                 std::printf("Usage: %s [owner_world.json] --world-assembler-prototype --stream-benchmark --stream-pipeline [options]\n"
                     "  --workers=N --clip-radius=N --max-clip-level=N --max-level=N\n"
                     "  --camera=X,Y,Z,YAW,PITCH (position in metres) --stream-hash\n"
+                    "  --stream-scheduler-policy=0|1|2 (L77 coarse, L78 near, L79 fair share)\n"
+                    "  --moving-camera-speed-mps=N [--moving-camera-duration-s=N] [--moving-camera-dwell-s=N]\n"
                     "  --stream-hash-tiles (print per-tile hashes; implies --stream-hash)\n"
                     "  --stream-hash-tiles-allow-skips (mesh/topology falsifier with proven uniform skips)\n"
                     "  --camera-step=X,Y,Z (optional second view step in metres)\n"
@@ -1590,6 +1597,37 @@ namespace
                 {std::fprintf(stderr,"Invalid --camera-step value: %.*s\n",static_cast<int>(arg.size()),arg.data());return false;}
                 options.HasCameraStep=true;
             }
+            else if(arg.starts_with("--stream-scheduler-policy="))
+            {
+                if(!readInt("--stream-scheduler-policy=",options.StreamingSchedulerPolicy)
+                    ||options.StreamingSchedulerPolicy<0||options.StreamingSchedulerPolicy>2)
+                {std::fprintf(stderr,"Invalid --stream-scheduler-policy (expected 0..2).\n");return false;}
+            }
+            else if(arg.starts_with("--moving-camera-speed-mps="))
+            {
+                const std::string value(arg.substr(std::string_view("--moving-camera-speed-mps=").size()));
+                char* end=nullptr;options.MovingCameraSpeedMetersPerSecond=std::strtod(value.c_str(),&end);
+                if(end==value.c_str()||*end!='\0'||!std::isfinite(options.MovingCameraSpeedMetersPerSecond)
+                    ||options.MovingCameraSpeedMetersPerSecond<=0.0)
+                {std::fprintf(stderr,"Invalid --moving-camera-speed-mps (expected positive finite value).\n");return false;}
+                options.MovingCameraTrace=true;
+            }
+            else if(arg.starts_with("--moving-camera-duration-s="))
+            {
+                const std::string value(arg.substr(std::string_view("--moving-camera-duration-s=").size()));
+                char* end=nullptr;options.MovingCameraDurationSeconds=std::strtod(value.c_str(),&end);
+                if(end==value.c_str()||*end!='\0'||!std::isfinite(options.MovingCameraDurationSeconds)
+                    ||options.MovingCameraDurationSeconds<=0.0)
+                {std::fprintf(stderr,"Invalid --moving-camera-duration-s (expected positive finite value).\n");return false;}
+            }
+            else if(arg.starts_with("--moving-camera-dwell-s="))
+            {
+                const std::string value(arg.substr(std::string_view("--moving-camera-dwell-s=").size()));
+                char* end=nullptr;options.MovingCameraDwellSeconds=std::strtod(value.c_str(),&end);
+                if(end==value.c_str()||*end!='\0'||!std::isfinite(options.MovingCameraDwellSeconds)
+                    ||options.MovingCameraDwellSeconds<0.0)
+                {std::fprintf(stderr,"Invalid --moving-camera-dwell-s (expected nonnegative finite value).\n");return false;}
+            }
             else if(arg.starts_with("--column-cache="))
             {
                 const std::string_view mode=arg.substr(std::string_view("--column-cache=").size());
@@ -1635,6 +1673,10 @@ namespace
         {std::fprintf(stderr,"--tls-probe-touch requires --tls-probe=N\n");return false;}
         if(options.RegionCrossing&&!options.HasCameraStep)
         {std::fprintf(stderr,"--region-crossing requires --camera-step=X,Y,Z\n");return false;}
+        if(options.MovingCameraTrace&&(!options.StreamPipeline||!options.WorldAssemblerPrototype))
+        {std::fprintf(stderr,"--moving-camera-speed-mps requires --world-assembler-prototype --stream-pipeline\n");return false;}
+        if(options.MovingCameraTrace&&options.StreamingSchedulerPolicy<0)
+        {std::fprintf(stderr,"--moving-camera-speed-mps requires --stream-scheduler-policy=0|1|2\n");return false;}
         if(options.LandmarkL45RampControl&&!options.LandmarkChamberDemo)
         {std::fprintf(stderr,"--landmark-l45-ramp-control requires --landmark-chamber-demo\n");return false;}
         if(options.AuditOreVeinYield&&!options.OreVeinsDemo)
@@ -2228,5 +2270,8 @@ int main(int argc,char** argv)
             ?options.ParallelSignEdgeRepair:options.FloatingIslandsRecipe,
         options.AuditNativeLattice,options.LatticeOrphanControl,
         options.CaptureSkipWalkability,options.ProfilePassageComposer,
-        options.StreamHashAllowUniformSkips,options.Linux77Profile);
+        options.StreamHashAllowUniformSkips,options.Linux77Profile,
+        options.StreamingSchedulerPolicy,options.MovingCameraTrace,
+        options.MovingCameraSpeedMetersPerSecond,options.MovingCameraDurationSeconds,
+        options.MovingCameraDwellSeconds);
 }