wip(step1): collision/upload clocks behind default-off switches -- partial, stopped on low memory

Compiled and run (cap 14 / 12 / 8), then stopped: another app held 12.5 GB, free memory fell
under the 6 GB launch floor and processes failed to start (STATUS_DLL_INIT_FAILED).

Measured so far (owner world, 120 s windows):
- 343 L0 tiles, request->collision-ready p50/p95: cap 14 = 262/440 ms, cap 8 = 196/238 ms;
  scheduler queue wait p95 141 ms -> 0.9 ms. Initial support tile at cap 14: RMC submit->body
  7.47 s, first check->ready 9.73 s; at cap 12: 0.33 s / 2.54 s; at cap 8 a 3,949-tri tile
  reached body update 2.8 ms after RMC submission. Waiting, not cooking, dominates.
- NOT confirmed: a capsule sweep hitting the exact target body (the 0.75 ms hit was another
  component); the 10 ms core-cook and 150 ms/27-tile thresholds are unscored.
- CMC cannot take a same-frame density floor: FindFloor/ComputeFloorDist trace the collision
  scene. Underfoot digs (100-dig test), upload throughput (render-enabled caps 4/8/16) and the
  8x per-sample question are not run. Per-sample profiling was fully disabled in these runs, so
  it does not explain the 8x.
Switches (all default off): voxel.Step1GenerationCap, Step1PauseGenerationAfterSeconds,
Step1MaxMeshApplies, Step1PrequeueVisibleLOD0, Step1UploadDisableCollision, Step1CollisionProbe,
Step1CoreCookBenchmark; harness -EnableRender. Also: plan step 3b, AVX2 need not match scalar.

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

Tools/VoxelForgeTest.ps1

@@ -3,6 +3,7 @@ param(
     [ValidateSet('canonical', 'owner', 'probe', 'perf', 'visual-edit', 'visual-lod', 'visual-gap-walk', 'visual-gap-inject', 'dig-motion', 'tests', 'surface-fall', 'crossing', 'gate-stress', 'parity', 'horizon', 'horizon-render', 'determinism', 'symbolize-stacks')]
     [string]$Scenario = 'canonical',
     [switch]$Build,
+    [switch]$EnableRender,
     [ValidateSet('owner', 'default')]
     [string]$Assets = 'owner',
     [hashtable]$Cvars = @{},
@@ -465,7 +466,7 @@ function Invoke-BuildProcess([string[]]$Arguments, [string]$LogPath, [string]$Er
             try { Stop-Process -Id ([int]$process.Id) -Force -ErrorAction Stop } catch { }
             throw "Could not lower owned build PID $($process.Id) to BelowNormal: $($_.Exception.Message)"
         }
-        $wait = Wait-OwnedProcess $process $LaunchTimeoutSeconds
+        $wait = Wait-OwnedProcess $process $LaunchTimeoutSeconds -EnforceMemoryLimit
     } finally {
         if ($null -eq $oldDotnetCliHome) { Remove-Item Env:DOTNET_CLI_HOME -ErrorAction SilentlyContinue } else { $env:DOTNET_CLI_HOME = $oldDotnetCliHome }
         if ($null -eq $oldDotnetFirstUse) { Remove-Item Env:DOTNET_SKIP_FIRST_TIME_EXPERIENCE -ErrorAction SilentlyContinue } else { $env:DOTNET_SKIP_FIRST_TIME_EXPERIENCE = $oldDotnetFirstUse }
@@ -479,12 +480,16 @@ function Invoke-BuildProcess([string[]]$Arguments, [string]$LogPath, [string]$Er
         ended_utc = [datetime]::UtcNow.ToString('o')
         exit_code = $wait.exit_code
         timed_out = [bool]$wait.timed_out
+        memory_limit_hit = [bool]$wait.memory_limit_hit
+        peak_private_bytes = [int64]$wait.peak_private_bytes
         log = $LogPath
         stdout = $StdoutPath
         error_log = $ErrorPath
         arguments = @($Arguments)
         isolated_local_app_data = $isolatedLocalAppData
-        status = if ($wait.timed_out) { 'timeout' } elseif ($wait.exit_code -eq 0) { 'passed' } else { 'failed' }
+        status = if ($wait.timed_out) { 'timeout' }
+            elseif ($wait.memory_limit_hit) { 'memory_limit' }
+            elseif ($wait.exit_code -eq 0) { 'passed' } else { 'failed' }
     }
 }
 
@@ -1490,7 +1495,7 @@ try {
             $baseCvars['voxel.UseBlockEarlyOut'] = 0
             $baseCvars['voxel.OuterClassifierMode'] = 0
             $baseCvars['voxel.SealedSolidProof'] = 0
-            $args = New-CommonArguments 'game' (Join-Path $RunRoot 'Logs\perf.log') (Merge-Cvars $baseCvars)
+            $args = New-CommonArguments 'game' (Join-Path $RunRoot 'Logs\perf.log') (Merge-Cvars $baseCvars) $EnableRender.IsPresent
             $gameLedger = Invoke-UnrealLaunch 'perf-game' $args `
                 (Join-Path $RunRoot 'Logs\perf.log') (Join-Path $RunRoot 'Logs\perf.stdout.log') (Join-Path $RunRoot 'Logs\perf.stderr.log')
             $GameMetrics = Get-StreamingMetrics (Join-Path $RunRoot 'Logs\perf.log')