wip(assembler): round S7 -- workers kept busy: in-game cold full view 17.5 s -> 7.8 s

Two admission blockers found by per-frame decline codes: the near reserve held
four slots idle after LOD0 was done (coarse capped at 6), and finished-but-
unapplied results counted against the task cap. Admission now counts queued +
running tasks; near reserve releases once the walkable ring is ready while
stationary (voxel.StreamingDynamicNearReserve, default on). Walkable ring
0.65 -> 0.58 s, full LOD0 2.28 -> 1.44 s, busy workers 2.2 -> 5.6 of 10.
Old behaviour behind voxel.StreamingLegacyPendingResultCap. RMC source reviewed
(read-only): batching/fast-cook ranked, not yet worth it on measured apply cost.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01MmSoF64BbRFmk9C3p1VsBJ

Source/VoxelForge/Public/VoxelWorld.h

@@ -443,7 +443,12 @@ public:
      *  capped to (logical cores − 2) so small CPUs don't thrash on a flat 16 (background
      *  priority stops frame starvation, not the context-switch overhead). */
     int32 GetMaxConcurrentTasks() const;
+    /** Submitted generation tasks still queued or running; completed MPSC results do not occupy admission.
+     *  Taches de generation soumises, en file ou en cours ; les resultats MPSC termines ne bloquent pas l'admission. */
     int32 GetActiveGenerationTaskCount() const;
+    /** Count queued/running work for admission; the legacy CVar can include finished results awaiting apply.
+     *  Compter le travail en file/en cours ; le CVar de compatibilite peut inclure les resultats finis en attente. */
+    int32 GetGenerationAdmissionCount() const;
     /** Reserve task slots for collision-critical/edit/LOD0 work; far work uses the remainder. */
     int32 GetNearTaskReserve(int32 MaxTasks) const;
 
@@ -1093,7 +1098,9 @@ public:
     TQueue<FChunkResult, EQueueMode::Mpsc> EditedProcessQueue;
     TQueue<FChunkResult, EQueueMode::Mpsc> NearProcessQueue;
     TQueue<FChunkResult, EQueueMode::Mpsc> ProcessQueue;
-    TSet<FVoxelTileKey> PendingTiles;   // tiles with a gen task in flight
+    // Keys stay pending from task submission until the game thread applies the result; completed results can wait here.
+    // Les cles restent en attente de la soumission jusqu'a l'application sur le thread de jeu ; les resultats termines y attendent.
+    TSet<FVoxelTileKey> PendingTiles;
     // Game-thread-owned map; workers retain the shared token and only read its atomic flag.
     TMap<FVoxelTileKey, TSharedPtr<FVoxelTileCancellationState, ESPMode::ThreadSafe>>
         PendingTileCancellation;
@@ -1121,7 +1128,8 @@ public:
     // Active pendant les mutations de génération lancées par l'éditeur, sans signifier la destruction.
     std::atomic<bool> bGenerationPaused{false};
 
-    // Number of async tasks currently running — EndPlay waits for this to reach 0
+    // Submitted async tasks (including UE-queued work) — EndPlay waits for this to reach 0.
+    // Taches asynchrones soumises (y compris la file UE) — EndPlay attend que le compteur revienne a 0.
     std::atomic<int32> ActiveTaskCount{0};
     // Active workers are counted inside the launched tile task, distinct from tasks queued by UE.
     // Les travailleurs actifs sont comptes dans la tache de tuile, distincts des taches en attente UE.
@@ -1199,6 +1207,11 @@ public:
     int32 EffectiveNearTaskReserve = -1;
     uint64 NextStreamingRequestOrdinal = 0;
     std::atomic<uint64> NextStreamingGenerationOrdinal{0};
+    // Cumulative worker-task wall cycles avoid aliasing the instantaneous per-frame counter.
+    // Les cycles cumules des taches evitent l'aliasing du compteur instantane echantillonne par frame.
+    std::atomic<uint64> TotalGenerationWorkerTaskCycles{0};
+    double LastStreamingSchedulerSampleSeconds = 0.0;
+    uint64 LastStreamingSchedulerWorkerCycles = 0;
 
     struct FReadyTransitionVisibilitySample
     {