perf(diag): complete trustworthy Slice A capture tooling

Correct whole-frame GPU timestamps so they bracket only the accepted render transaction and associate delayed query results with the owning CPU frame. Add route-wide frame-history summaries, fixed-camera screenshot comparison, process counters, contention traces, a pinned Arwic workload, and credential-safe launch disclosure.

The reference hardware/display contract now keeps local and RDP populations separate and defines the screenshot and re-baseline rules needed by later prepared-content gates.

Co-Authored-By: Codex <noreply@openai.com>

AcDream.slnx

@@ -17,6 +17,7 @@
   <Folder Name="/tests/">
     <Project Path="tests/AcDream.App.Tests/AcDream.App.Tests.csproj" />
     <Project Path="tests/AcDream.Bake.Tests/AcDream.Bake.Tests.csproj" />
+    <Project Path="tests/AcDream.Cli.Tests/AcDream.Cli.Tests.csproj" />
     <Project Path="tests/AcDream.Content.Tests/AcDream.Content.Tests.csproj" />
     <Project Path="tests/AcDream.Core.Tests.Fixtures.HelloPlugin/AcDream.Core.Tests.Fixtures.HelloPlugin.csproj" />
     <Project Path="tests/AcDream.Core.Tests/AcDream.Core.Tests.csproj" />

docs/research/2026-07-24-performance-capture-playbook.md

@@ -0,0 +1,113 @@
+# Performance capture playbook
+
+This is the reproducible Slice A capture procedure for the Modern Runtime
+Architecture plan. The machine and graphical contract is
+[`2026-07-24-performance-reference-configuration.json`](2026-07-24-performance-reference-configuration.json).
+
+## Connected captures
+
+Build once from a clean tracked worktree:
+
+```powershell
+dotnet build AcDream.slnx -c Release
+```
+
+Run the capped nine-stop route:
+
+```powershell
+.\tools\run-connected-r6-soak.ps1 `
+  -Repository (Get-Location).Path `
+  -SkipBuild `
+  -CaptureContention
+```
+
+Run the uncapped nine-stop route:
+
+```powershell
+.\tools\run-connected-r6-soak.ps1 `
+  -Repository (Get-Location).Path `
+  -SkipBuild `
+  -Uncapped
+```
+
+Run the pinned uncapped Arwic scene:
+
+```powershell
+.\tools\run-connected-r6-soak.ps1 `
+  -Repository (Get-Location).Path `
+  -SkipBuild `
+  -Uncapped `
+  -DenseTown
+```
+
+Credentials come from `ACDREAM_TEST_USER` and `ACDREAM_TEST_PASS`, or the
+script's local test defaults. The generated environment disclosure redacts
+secret-like variable names. Never commit credentials, raw stdout/stderr,
+counter CSVs, `.nettrace`, or machine-local absolute paths.
+
+Every run captures:
+
+- Per-frame CPU, GL GPU, frame-thread allocation, and stage history.
+- Route-wide and five-second checkpoint percentiles.
+- Per-portal windows from 10 seconds before through 5 seconds after
+  materialization, including the 20 worst frames.
+- Process-wide `System.Runtime` counters at one-second cadence.
+- Canonical resource/checkpoint JSON and named screenshots.
+- Optional CLR contention events with call stacks.
+
+`-SkipRuntimeCounters` exists for measurement-overhead experiments only. A
+baseline captured with it is incomplete.
+
+## Allocation and contention attribution
+
+The per-frame history answers which frame and which update/upload phase was
+expensive. Canonical checkpoint deltas and `runtime-counters.csv` answer
+whether allocations were merely moved to workers.
+
+For per-thread allocation stacks, make a separate reproduction capture so the
+observer cost is not mixed into the baseline:
+
+```powershell
+dotnet-trace collect `
+  --process-id <pid> `
+  --providers Microsoft-Windows-DotNETRuntime:0x0000000000000001:5 `
+  --duration 00:00:00:30 `
+  --output allocation-stacks.nettrace
+```
+
+The provider enables CLR GC events at verbose level; inspect allocation-tick
+stacks grouped by managed thread in PerfView or Visual Studio. Interpret
+sampled bytes as attribution weights, not exact object sizes.
+
+The soak's `-CaptureContention` mode captures the CLR contention keyword
+(`0x4000`) at verbose level. Inspect `ContentionStart` call stacks and group by
+lock acquisition site. The first comparisons are the DAT typed-object lock,
+`ObjectMeshManager` pending-request ownership, and any newly dominant caller;
+do not optimize a lock solely from event count.
+
+## Screenshot contract
+
+Compare a candidate against the matching reference image:
+
+```powershell
+dotnet .\src\AcDream.Cli\bin\Release\net10.0\AcDream.Cli.dll `
+  compare-screenshots `
+  <reference.png> `
+  <candidate.png> `
+  <comparison.json> `
+  2 `
+  0.001 `
+  <optional-mask.png>
+```
+
+The routes pin world time and camera input. A nonzero-alpha mask excludes
+known dynamic pixels such as DAT particles. Never widen the global tolerance
+to conceal a deterministic geometry, texture, visibility, or UI difference.
+
+## Baseline authority
+
+Name every committed compact result `capped-local`, `uncapped-local`,
+`capped-rdp`, or `uncapped-rdp`. RDP captures are diagnostic only for
+throughput. An authoritative local baseline must be run on the physical AMD
+display path defined in the reference configuration. A baseline report records
+the exact commit and must have a clean tracked source status.

docs/research/2026-07-24-performance-reference-configuration.json

@@ -0,0 +1,74 @@
+{
+  "schemaVersion": 1,
+  "recordedUtc": "2026-07-24T00:00:00Z",
+  "referenceHardware": {
+    "cpu": {
+      "name": "AMD Ryzen 7 9800X3D 8-Core Processor",
+      "physicalCores": 8,
+      "logicalProcessors": 16
+    },
+    "memoryBytes": 34359738368,
+    "gpu": {
+      "name": "AMD Radeon RX 9070 XT",
+      "driverVersion": "32.0.31021.5001"
+    },
+    "os": {
+      "name": "Microsoft Windows 11 Pro",
+      "version": "10.0.26200",
+      "build": "26200",
+      "architecture": "x64"
+    },
+    "dotnetSdk": "10.0.300"
+  },
+  "displayPaths": {
+    "authoritativeLocal": {
+      "adapter": "AMD Radeon RX 9070 XT",
+      "desktopResolution": "2560x1440",
+      "refreshHz": 240,
+      "authority": "performance-gate"
+    },
+    "diagnosticRdp": {
+      "adapter": "Microsoft Remote Display Adapter",
+      "desktopResolution": "2056x1290",
+      "refreshHz": 32,
+      "authority": "diagnostic-only"
+    }
+  },
+  "clientConfiguration": {
+    "build": "Release",
+    "windowMode": "windowed",
+    "renderResolution": "1280x720",
+    "quality": "High",
+    "fieldOfViewDegrees": 60,
+    "vsync": false,
+    "retailUi": true,
+    "developerUi": false,
+    "audio": true,
+    "datSource": "local retail EoR DAT files",
+    "server": "local ACE"
+  },
+  "routes": {
+    "canonicalNineStop": "tools/connected-r6-soak.route.txt",
+    "denseTown": {
+      "name": "Arwic",
+      "route": "tools/connected-dense-town.route.txt",
+      "arrival": "ACE canonical /telepoi Arwic position and heading",
+      "camera": "six seconds of MovementTurnRight after materialization",
+      "timeOfDay": 0.5
+    }
+  },
+  "screenshotComparison": {
+    "channelTolerance": 2,
+    "maxDifferentPixelFraction": 0.001,
+    "timeOfDay": 0.5,
+    "dynamicPixelRule": "Particles and other nondeterministic dynamic pixels must be excluded by an explicit same-resolution alpha mask. An unmasked failure is never waived by increasing the global tolerance."
+  },
+  "baselineRules": [
+    "Capped-local, uncapped-local, capped-RDP, and uncapped-RDP captures are separate populations and are never compared as if interchangeable.",
+    "Only an authoritative-local capture may establish or pass FPS, CPU, GPU, or frame-time budgets.",
+    "RDP captures may validate automation, lifetime, allocation attribution, and large regressions, but are labeled diagnostic-only.",
+    "Re-baseline after a CPU, GPU, driver, OS build, physical display path, render resolution, quality, FOV, VSync, DAT set, route, or measurement-schema change.",
+    "A re-baseline records the source commit and keeps the prior committed baseline for historical comparison unless its data is invalid.",
+    "Performance captures use a clean tracked worktree and disclose all ACDREAM_* launch variables with secrets redacted."
+  ]
+}

docs/research/2026-07-24-performance-reference-configuration.md

@@ -0,0 +1,22 @@
+# Performance reference configuration
+
+The machine-readable contract is
+[`2026-07-24-performance-reference-configuration.json`](2026-07-24-performance-reference-configuration.json).
+It fixes the reference CPU/GPU/driver/OS, graphical settings, routes, display
+paths, screenshot rule, and re-baseline policy used by the Modern Runtime
+Architecture plan.
+
+Only the physical AMD display path is authoritative for frame-time, CPU, and
+GPU acceptance gates. Remote Desktop runs are intentionally retained as a
+separate diagnostic population: they validate the connected route, resource
+lifetime, allocation attribution, and major regressions, but the 32 Hz remote
+presentation path cannot establish maximum throughput.
+
+The connected routes pin the client-only world-time override at noon. The
+dense-town route uses ACE's canonical Arwic point-of-interest arrival and a
+fixed six-second retail-input turn before its screenshot and checkpoint.
+
+Screenshot comparison uses a per-channel tolerance of 2 and permits at most
+0.1% differing unmasked pixels. Dynamic particles or similarly nondeterministic
+pixels require an explicit same-resolution alpha mask; a failure is not
+accepted by silently increasing the global tolerance.

src/AcDream.App/Composition/FrameRootComposition.cs

@@ -256,9 +256,7 @@ internal sealed class FrameRootCompositionPhase
                 interaction.RetainedUi?.Host.TextRenderer,
                 live.ClipFrame,
                 foundation.Terrain,
-                foundation.SceneLighting,
-                d.FrameProfiler,
-                d.Gl),
+                foundation.SceneLighting),
             new RuntimeRenderFrameClearPhase(
                 d.Gl,
                 d.WorldTime,
@@ -454,6 +452,7 @@ internal sealed class FrameRootCompositionPhase
             renderWeatherFrame);
         var renderFrame = new RenderFrameOrchestrator(
             host.GpuFrameFlights,
+            new FrameProfilerGpuMeasurement(d.FrameProfiler, d.Gl),
             framePreparation,
             worldSceneRenderer,
             privatePresentation,

src/AcDream.App/Diagnostics/FrameProfiler.cs

@@ -32,35 +32,25 @@ public enum FrameStage
 /// together. <c>GpuUs</c> is <c>-1</c> for a frame with no available GPU
 /// sample (warm-up, or <c>ACDREAM_WB_DIAG=1</c> self-disable).
 /// </summary>
-internal readonly struct FrameHistoryRecord(
-    int frameIndex,
-    double timestampMs,
-    long cpuUs,
-    long gpuUs,
-    long allocBytes,
-    long updateUs,
-    long uploadUs,
-    long imGuiUs,
-    long pacingUs)
-{
-    public readonly int FrameIndex = frameIndex;
-    public readonly double TimestampMs = timestampMs;
-    public readonly long CpuUs = cpuUs;
-    public readonly long GpuUs = gpuUs;
-    public readonly long AllocBytes = allocBytes;
-    public readonly long UpdateUs = updateUs;
-    public readonly long UploadUs = uploadUs;
-    public readonly long ImGuiUs = imGuiUs;
-    public readonly long PacingUs = pacingUs;
-}
+internal readonly record struct FrameHistoryRecord(
+    int FrameIndex,
+    double TimestampMs,
+    long CpuUs,
+    long GpuUs,
+    long AllocBytes,
+    long UpdateUs,
+    long UploadUs,
+    long ImGuiUs,
+    long PacingUs);
 
 /// <summary>
 /// MP0 (2026-07-05) — the permanent honest frame profiler. One
-/// <c>FrameBoundary</c> call at the top of <c>GameWindow.OnRender</c>
+/// <c>FrameBoundary</c> call at the top of the accepted render transaction
 /// measures CPU frame time as the delta between consecutive boundaries
-/// (captures the FULL frame including present), brackets the frame in a
-/// GPU <c>TimeElapsed</c> query (via <see cref="GpuFrameTimer"/>), and
-/// samples per-frame allocated bytes + GC collection counts. Stage scopes
+/// (captures the FULL frame including present) and samples per-frame allocated
+/// bytes + GC collection counts. <see cref="BeginGpuFrame"/> and
+/// <see cref="EndGpuFrame"/> separately bracket only submitted render work.
+/// Stage scopes
 /// (<see cref="BeginStage"/>) attribute CPU time to Update / Upload /
 /// ImGui. Emits one <c>[frame-prof]</c> line every ~5 s while
 /// <see cref="RenderingDiagnostics.FrameProfEnabled"/> is true; costs one
@@ -79,8 +69,9 @@ internal readonly struct FrameHistoryRecord(
 /// preallocated, grow-as-needed <see cref="List{T}"/> (1 int + 1 double +
 /// 7 longs ≈ 72 bytes/record; a multi-hour capture at 165 fps is roughly
 /// 165 * 3600 * 72 bytes ≈ 43 MB/hour — fine for a bounded diagnostic run,
-/// not for unattended day-long capture). ZERO frame-thread I/O: the list only grows during
-/// <see cref="FrameBoundary"/>; the CSV is written once, from
+/// not for unattended day-long capture). Its initial capacity is about 9 MiB
+/// and covers the canonical route above 300 FPS without a frame-thread resize.
+/// ZERO frame-thread I/O: the CSV is written once, from
 /// <see cref="Dispose"/>, at shutdown. Recording only takes effect while
 /// <see cref="RenderingDiagnostics.FrameProfEnabled"/> is ALSO true — it
 /// reuses that instrumentation rather than duplicating it. Does not
@@ -90,7 +81,7 @@ internal readonly struct FrameHistoryRecord(
 public sealed class FrameProfiler : IDisposable
 {
     private const int WindowCapacity = 2048;              // ~12 s at 165 fps
-    private const int HistoryInitialCapacity = 4096;
+    private const int HistoryInitialCapacity = 131072;
     private const long ReportIntervalTicks = 5 * TimeSpan.TicksPerSecond;
     private static readonly int StageCount = Enum.GetValues<FrameStage>().Length;
 
@@ -104,7 +95,8 @@ public sealed class FrameProfiler : IDisposable
         Environment.GetEnvironmentVariable("ACDREAM_WB_DIAG") == "1";
     private readonly List<FrameHistoryRecord>? _history;
     private readonly long _profilerStartTimestamp;
-    private int _historyFrameIndex;
+    private readonly DateTime _profilerStartUtc;
+    private int _currentFrameIndex = -1;
 
     private GpuFrameTimer? _gpuTimer;
     private long _lastBoundaryTimestamp;
@@ -127,12 +119,14 @@ public sealed class FrameProfiler : IDisposable
         _stageAccumTicks = new long[StageCount];
         _lastStageUs = new long[StageCount];
         _profilerStartTimestamp = Stopwatch.GetTimestamp();
+        _profilerStartUtc = DateTime.UtcNow;
         if (RenderingDiagnostics.FrameHistoryPath is not null)
             _history = new List<FrameHistoryRecord>(HistoryInitialCapacity);
     }
 
     /// <summary>
-    /// Call as the FIRST statement of <c>GameWindow.OnRender</c>.
+    /// Call once at the accepted render-transaction boundary, before
+    /// <see cref="BeginGpuFrame"/>.
     /// </summary>
     public void FrameBoundary(GL gl)
     {
@@ -150,6 +144,7 @@ public sealed class FrameProfiler : IDisposable
                 _gpuTimer = null;
                 _wasEnabled = false;
                 _lastBoundaryTimestamp = 0;
+                _currentFrameIndex = -1;
             }
             return;
         }
@@ -164,8 +159,6 @@ public sealed class FrameProfiler : IDisposable
         long now = Stopwatch.GetTimestamp();
         long allocNow = GC.GetAllocatedBytesForCurrentThread();
 
-        bool historyFrame = false;
-        long historyCpuUs = 0, historyAllocBytes = 0;
         if (!_wasEnabled)
         {
             // First enabled frame (startup or runtime toggle-on): establish
@@ -179,6 +172,7 @@ public sealed class FrameProfiler : IDisposable
             Array.Clear(_stageAccumTicks);
             _gc0Base = GC.CollectionCount(0); _gc1Base = GC.CollectionCount(1); _gc2Base = GC.CollectionCount(2);
             if (_gpuTimer is null && !_wbDiagActive) _gpuTimer = new GpuFrameTimer(gl);
+            _currentFrameIndex = 0;
             if (_wbDiagActive && !_wbDiagNoticePrinted)
             {
                 _wbDiagNoticePrinted = true;
@@ -199,32 +193,25 @@ public sealed class FrameProfiler : IDisposable
                 _stageAccumTicks[i] = 0;
             }
             _framesInWindow++;
-            historyFrame = _history is not null;
-            historyCpuUs = cpuUs;
-            historyAllocBytes = allocDelta;
+            if (_history is not null)
+            {
+                _history.Add(new FrameHistoryRecord(
+                    _currentFrameIndex,
+                    (now - _profilerStartTimestamp) * 1000.0 / Stopwatch.Frequency,
+                    cpuUs,
+                    -1L,
+                    allocDelta,
+                    _lastStageUs[(int)FrameStage.Update],
+                    _lastStageUs[(int)FrameStage.Upload],
+                    _lastStageUs[(int)FrameStage.ImGui],
+                    _lastStageUs[(int)FrameStage.Pacing]));
+            }
+            _currentFrameIndex++;
         }
 
         _lastBoundaryTimestamp = now;
         _lastAllocBytes = allocNow;
 
-        long? gpuUsSample = _gpuTimer?.FrameBoundary();
-        if (gpuUsSample is long gpuUs)
-            _gpuUs.Push(gpuUs);
-
-        if (historyFrame)
-        {
-            _history!.Add(new FrameHistoryRecord(
-                _historyFrameIndex++,
-                (now - _profilerStartTimestamp) * 1000.0 / Stopwatch.Frequency,
-                historyCpuUs,
-                gpuUsSample ?? -1L,
-                historyAllocBytes,
-                _lastStageUs[(int)FrameStage.Update],
-                _lastStageUs[(int)FrameStage.Upload],
-                _lastStageUs[(int)FrameStage.ImGui],
-                _lastStageUs[(int)FrameStage.Pacing]));
-        }
-
         long nowTicks = DateTime.UtcNow.Ticks;
         if (nowTicks - _lastReportTicks >= ReportIntervalTicks && _framesInWindow > 0)
         {
@@ -242,6 +229,38 @@ public sealed class FrameProfiler : IDisposable
         }
     }
 
+    /// <summary>
+    /// Begin GPU timing immediately before render-resource, world, and private
+    /// presentation submission. Completed delayed samples are associated with
+    /// their owning history row rather than the frame that happened to poll
+    /// them.
+    /// </summary>
+    public void BeginGpuFrame()
+    {
+        if (!_wasEnabled || _gpuTimer is null || _currentFrameIndex < 0)
+            return;
+
+        Span<GpuFrameSample> completed = stackalloc GpuFrameSample[4];
+        int completedCount = _gpuTimer.BeginFrame(_currentFrameIndex, completed);
+        for (int index = 0; index < completedCount; index++)
+        {
+            GpuFrameSample sample = completed[index];
+            _gpuUs.Push(sample.ElapsedUs);
+            if (_history is not null
+                && (uint)sample.FrameIndex < (uint)_history.Count)
+            {
+                FrameHistoryRecord row = _history[sample.FrameIndex];
+                _history[sample.FrameIndex] = row with { GpuUs = sample.ElapsedUs };
+            }
+        }
+    }
+
+    /// <summary>End GPU timing immediately after render submission.</summary>
+    public void EndGpuFrame()
+    {
+        _gpuTimer?.EndFrame();
+    }
+
     /// <summary>
     /// Attribute the enclosed CPU time to <paramref name="stage"/>.
     /// Usage: <c>using var _ = profiler.BeginStage(FrameStage.Update);</c>.
@@ -283,14 +302,22 @@ public sealed class FrameProfiler : IDisposable
     }
 
     /// <summary>Pure CSV formatter — unit-tested; invariant culture. One header row plus one row per record.</summary>
-    internal static void WriteHistoryCsv(IEnumerable<FrameHistoryRecord> records, TextWriter writer)
+    internal static void WriteHistoryCsv(
+        IEnumerable<FrameHistoryRecord> records,
+        TextWriter writer,
+        DateTime profilerStartUtc)
     {
         var ci = CultureInfo.InvariantCulture;
-        writer.WriteLine("frame,timestamp_ms,cpu_us,gpu_us,alloc_bytes,update_us,upload_us,imgui_us,pacing_us");
+        DateTime startUtc = profilerStartUtc.ToUniversalTime();
+        writer.WriteLine(
+            "frame,timestamp_ms,timestamp_utc,cpu_us,gpu_us,alloc_bytes,"
+            + "update_us,upload_us,imgui_us,pacing_us");
         foreach (FrameHistoryRecord r in records)
         {
             writer.Write(r.FrameIndex.ToString(ci)); writer.Write(',');
             writer.Write(r.TimestampMs.ToString("0.000", ci)); writer.Write(',');
+            writer.Write(startUtc.AddMilliseconds(r.TimestampMs).ToString("O", ci));
+            writer.Write(',');
             writer.Write(r.CpuUs.ToString(ci)); writer.Write(',');
             writer.Write(r.GpuUs.ToString(ci)); writer.Write(',');
             writer.Write(r.AllocBytes.ToString(ci)); writer.Write(',');
@@ -316,7 +343,7 @@ public sealed class FrameProfiler : IDisposable
             try
             {
                 using var writer = new StreamWriter(path, append: false);
-                WriteHistoryCsv(_history, writer);
+                WriteHistoryCsv(_history, writer, _profilerStartUtc);
                 Console.WriteLine($"[frame-prof] wrote {_history.Count} history record(s) to '{path}'");
             }
             catch (Exception ex)

src/AcDream.App/Diagnostics/GpuFrameTimer.cs

@@ -3,18 +3,27 @@ using Silk.NET.OpenGL;
 
 namespace AcDream.App.Diagnostics;
 
+internal readonly record struct GpuFrameSample(int FrameIndex, long ElapsedUs);
+
 /// <summary>
-/// MP0 (2026-07-05) — whole-frame GPU time via a ring of
+/// MP0 (2026-07-05) — render-transaction GPU time via a ring of
 /// <see cref="QueryTarget.TimeElapsed"/> queries (depth 4, so results are
-/// read ~3 frames late and never stall). Mirrors WbDrawDispatcher's query
+/// read several frames late and never stall). Mirrors WbDrawDispatcher's query
 /// idiom including the #125 lesson: a glGenQueries name is not a query
 /// OBJECT until first glBeginQuery, so never-begun slots are skipped via
-/// the Begun flags.
+/// the pending flags.
 ///
 /// <para>MUST NOT be active while ACDREAM_WB_DIAG=1: GL forbids two
 /// simultaneously active TimeElapsed queries and WbDrawDispatcher brackets
 /// its passes with them under that flag. The caller (FrameProfiler)
 /// enforces the exclusion; this class just does the ring.</para>
+///
+/// <para>The query begins immediately before render-resource/world/private
+/// presentation submission and ends immediately after it. It is deliberately
+/// NOT left active until the next render callback: doing so includes display
+/// pacing and an arbitrary CPU idle interval in the GPU clock. Completed
+/// samples retain the frame index that owned the query so the delayed result
+/// can be paired with the correct CPU/history row.</para>
 /// </summary>
 internal sealed class GpuFrameTimer : IDisposable
 {
@@ -22,9 +31,10 @@ internal sealed class GpuFrameTimer : IDisposable
 
     private readonly GL _gl;
     private readonly uint[] _queries = new uint[RingDepth];
-    private readonly bool[] _begun = new bool[RingDepth];
-    private int _frameIndex;
-    private bool _queryActive;
+    private readonly bool[] _pending = new bool[RingDepth];
+    private readonly int[] _frameIndices = new int[RingDepth];
+    private int _nextSlot;
+    private int _activeSlot = -1;
 
     public GpuFrameTimer(GL gl)
     {
@@ -34,48 +44,74 @@ internal sealed class GpuFrameTimer : IDisposable
     }
 
     /// <summary>
-    /// Call once per frame at the frame boundary. Ends the previous
-    /// frame's query, polls the oldest slot non-blocking, begins this
-    /// frame's query. Returns the completed GPU time in microseconds for
-    /// a ~RingDepth-frames-old frame, or null when no result is ready.
+    /// Poll every ended query non-blocking, then begin this frame's render
+    /// transaction in the first free ring slot. If all slots are still in
+    /// flight the current frame is intentionally left unmeasured rather than
+    /// stalling or overwriting a pending result.
     /// </summary>
-    public long? FrameBoundary()
+    public int BeginFrame(int frameIndex, Span<GpuFrameSample> completed)
     {
-        if (_queryActive)
+        if (_activeSlot >= 0)
+            throw new InvalidOperationException("GPU frame timing was begun twice without an end.");
+        if (completed.Length < RingDepth)
+            throw new ArgumentException(
+                $"Completed-sample storage must hold at least {RingDepth} entries.",
+                nameof(completed));
+
+        int completedCount = 0;
+        for (int slot = 0; slot < RingDepth; slot++)
         {
-            _gl.EndQuery(QueryTarget.TimeElapsed);
-            _queryActive = false;
+            if (!_pending[slot])
+                continue;
+
+            _gl.GetQueryObject(
+                _queries[slot],
+                QueryObjectParameterName.ResultAvailable,
+                out int available);
+            if (available == 0)
+                continue;
+
+            _gl.GetQueryObject(
+                _queries[slot],
+                QueryObjectParameterName.Result,
+                out ulong elapsedNanoseconds);
+            completed[completedCount++] = new GpuFrameSample(
+                _frameIndices[slot],
+                (long)(elapsedNanoseconds / 1000UL));
+            _pending[slot] = false;
         }
 
-        long? completedUs = null;
-        int readSlot = _frameIndex % RingDepth;   // about to be reused — oldest
-        if (_begun[readSlot])
+        for (int offset = 0; offset < RingDepth; offset++)
         {
-            _gl.GetQueryObject(_queries[readSlot], QueryObjectParameterName.ResultAvailable, out int avail);
-            if (avail != 0)
-            {
-                _gl.GetQueryObject(_queries[readSlot], QueryObjectParameterName.Result, out ulong ns);
-                completedUs = (long)(ns / 1000UL);
-            }
-            // Not available ⇒ sample silently dropped (same policy as
-            // WbDrawDispatcher) — percentiles tolerate missing samples.
+            int slot = (_nextSlot + offset) % RingDepth;
+            if (_pending[slot])
+                continue;
+
+            _gl.BeginQuery(QueryTarget.TimeElapsed, _queries[slot]);
+            _frameIndices[slot] = frameIndex;
+            _activeSlot = slot;
+            _nextSlot = (slot + 1) % RingDepth;
+            break;
         }
 
-        _gl.BeginQuery(QueryTarget.TimeElapsed, _queries[readSlot]);
-        _begun[readSlot] = true;
-        _queryActive = true;
-        _frameIndex++;
-        return completedUs;
+        return completedCount;
     }
 
-    /// <summary>End any active query without beginning a new one (used when the profiler is toggled off mid-session).</summary>
+    /// <summary>End the query around the current render transaction.</summary>
+    public void EndFrame()
+    {
+        if (_activeSlot < 0)
+            return;
+
+        _gl.EndQuery(QueryTarget.TimeElapsed);
+        _pending[_activeSlot] = true;
+        _activeSlot = -1;
+    }
+
+    /// <summary>End an active query without beginning another.</summary>
     public void Stop()
     {
-        if (_queryActive)
-        {
-            _gl.EndQuery(QueryTarget.TimeElapsed);
-            _queryActive = false;
-        }
+        EndFrame();
     }
 
     public void Dispose()

src/AcDream.App/Rendering/FrameProfilerGpuMeasurement.cs

@@ -0,0 +1,32 @@
+using AcDream.App.Diagnostics;
+using Silk.NET.OpenGL;
+
+namespace AcDream.App.Rendering;
+
+/// <summary>
+/// Production render-transaction measurement adapter. CPU frame boundaries
+/// remain owned by <see cref="FrameProfiler"/> while this adapter places the
+/// GPU query around only the GL-producing render phases.
+/// </summary>
+internal sealed class FrameProfilerGpuMeasurement : IRenderFrameGpuMeasurement
+{
+    private readonly FrameProfiler _profiler;
+    private readonly GL _gl;
+
+    public FrameProfilerGpuMeasurement(FrameProfiler profiler, GL gl)
+    {
+        _profiler = profiler ?? throw new ArgumentNullException(nameof(profiler));
+        _gl = gl ?? throw new ArgumentNullException(nameof(gl));
+    }
+
+    public void BeginFrame()
+    {
+        _profiler.FrameBoundary(_gl);
+        _profiler.BeginGpuFrame();
+    }
+
+    public void EndFrame()
+    {
+        _profiler.EndGpuFrame();
+    }
+}

src/AcDream.App/Rendering/RenderFrameOrchestrator.cs

@@ -43,6 +43,18 @@ internal interface IRenderFrameResourcePhase
     void Prepare(RenderFrameInput input);
 }
 
+/// <summary>
+/// Diagnostic GPU timer bracketing only render-resource, world, and private
+/// presentation submission. It deliberately excludes diagnostics, pacing,
+/// and the idle interval before the next render callback.
+/// </summary>
+internal interface IRenderFrameGpuMeasurement
+{
+    void BeginFrame();
+
+    void EndFrame();
+}
+
 internal interface IWorldSceneFramePhase
 {
     WorldRenderFrameOutcome Render(RenderFrameInput input);
@@ -117,6 +129,7 @@ internal sealed class NullRenderFrameFailureRecovery : IRenderFrameFailureRecove
 internal sealed class RenderFrameOrchestrator : IGameRenderFrameRoot
 {
     private readonly IRenderFrameLifetime _lifetime;
+    private readonly IRenderFrameGpuMeasurement _gpuMeasurement;
     private readonly IRenderFrameResourcePhase _resources;
     private readonly IWorldSceneFramePhase _world;
     private readonly IPrivatePresentationFramePhase _presentation;
@@ -126,6 +139,7 @@ internal sealed class RenderFrameOrchestrator : IGameRenderFrameRoot
 
     public RenderFrameOrchestrator(
         IRenderFrameLifetime lifetime,
+        IRenderFrameGpuMeasurement gpuMeasurement,
         IRenderFrameResourcePhase resources,
         IWorldSceneFramePhase world,
         IPrivatePresentationFramePhase presentation,
@@ -134,6 +148,8 @@ internal sealed class RenderFrameOrchestrator : IGameRenderFrameRoot
         IRenderFrameFailureRecovery recovery)
     {
         _lifetime = lifetime ?? throw new ArgumentNullException(nameof(lifetime));
+        _gpuMeasurement = gpuMeasurement
+            ?? throw new ArgumentNullException(nameof(gpuMeasurement));
         _resources = resources ?? throw new ArgumentNullException(nameof(resources));
         _world = world ?? throw new ArgumentNullException(nameof(world));
         _presentation = presentation ?? throw new ArgumentNullException(nameof(presentation));
@@ -149,10 +165,37 @@ internal sealed class RenderFrameOrchestrator : IGameRenderFrameRoot
         Exception? renderFailure = null;
         try
         {
-            _resources.Prepare(input);
-            WorldRenderFrameOutcome world = _world.Render(input);
-            PrivatePresentationFrameOutcome presentation =
-                _presentation.Render(input, world);
+            WorldRenderFrameOutcome world;
+            PrivatePresentationFrameOutcome presentation;
+            Exception? measuredRenderFailure = null;
+            _gpuMeasurement.BeginFrame();
+            try
+            {
+                _resources.Prepare(input);
+                world = _world.Render(input);
+                presentation = _presentation.Render(input, world);
+            }
+            catch (Exception error)
+            {
+                measuredRenderFailure = error;
+                throw;
+            }
+            finally
+            {
+                try
+                {
+                    _gpuMeasurement.EndFrame();
+                }
+                catch (Exception measurementFailure)
+                    when (measuredRenderFailure is not null)
+                {
+                    throw new AggregateException(
+                        "Rendering failed and its GPU measurement could not be closed.",
+                        measuredRenderFailure,
+                        measurementFailure);
+                }
+            }
+
             var outcome = new RenderFrameOutcome(world, presentation);
             _diagnostics.Publish(input, outcome);
             _postDiagnostics.Process(input, outcome);

src/AcDream.App/Rendering/RenderFrameResourceController.cs

@@ -93,9 +93,6 @@ internal sealed class RuntimeRenderFrameBeginResources : IRenderFrameBeginResour
     private readonly ClipFrame? _clip;
     private readonly TerrainModernRenderer? _terrain;
     private readonly SceneLightingUboBinding? _lighting;
-    private readonly FrameProfiler _profiler;
-    private readonly GL _gl;
-
     public RuntimeRenderFrameBeginResources(
         TextureCache? textures,
         WbDrawDispatcher? dispatcher,
@@ -105,9 +102,7 @@ internal sealed class RuntimeRenderFrameBeginResources : IRenderFrameBeginResour
         TextRenderer? uiText,
         ClipFrame? clip,
         TerrainModernRenderer? terrain,
-        SceneLightingUboBinding? lighting,
-        FrameProfiler profiler,
-        GL gl)
+        SceneLightingUboBinding? lighting)
     {
         _textures = textures;
         _dispatcher = dispatcher;
@@ -118,8 +113,6 @@ internal sealed class RuntimeRenderFrameBeginResources : IRenderFrameBeginResour
         _clip = clip;
         _terrain = terrain;
         _lighting = lighting;
-        _profiler = profiler ?? throw new ArgumentNullException(nameof(profiler));
-        _gl = gl ?? throw new ArgumentNullException(nameof(gl));
     }
 
     public void Begin(int gpuSlot)
@@ -134,7 +127,6 @@ internal sealed class RuntimeRenderFrameBeginResources : IRenderFrameBeginResour
         _clip?.BeginFrame(gpuSlot);
         _terrain?.BeginFrame(gpuSlot);
         _lighting?.BeginFrame(gpuSlot);
-        _profiler.FrameBoundary(_gl);
     }
 }
 

src/AcDream.Cli/PerformanceTools.cs

@@ -0,0 +1,533 @@
+using System.Globalization;
+using System.Text.Json;
+using System.Text.RegularExpressions;
+using SixLabors.ImageSharp;
+using SixLabors.ImageSharp.PixelFormats;
+
+namespace AcDream.Cli;
+
+public static partial class PerformanceTools
+{
+    private static readonly JsonSerializerOptions JsonOptions = new()
+    {
+        PropertyNamingPolicy = JsonNamingPolicy.CamelCase,
+        WriteIndented = true,
+    };
+
+    public static int SummarizeFrameHistory(string[] args)
+    {
+        if (args.Length < 4)
+        {
+            Console.Error.WriteLine(
+                "usage: AcDream.Cli summarize-frame-history "
+                + "<frame-history.csv> <checkpoints.jsonl> <markers.log> <out.json>");
+            return 2;
+        }
+
+        try
+        {
+            IReadOnlyList<FrameRow> frames = ReadFrames(args[0]);
+            IReadOnlyList<CheckpointRow> checkpoints = ReadCheckpoints(args[1]);
+            IReadOnlyList<PortalMarker> portals = ReadPortalMarkers(args[2]);
+            var summary = new FrameHistoryReport(
+                SourceFrameHistory: Path.GetFileName(args[0]),
+                FrameCount: frames.Count,
+                FirstFrameUtc: frames.Count == 0 ? null : frames[0].TimestampUtc,
+                LastFrameUtc: frames.Count == 0 ? null : frames[^1].TimestampUtc,
+                Route: SummarizeWindow(frames),
+                CheckpointWindows: checkpoints.Select(checkpoint =>
+                    new NamedWindowSummary(
+                        checkpoint.Name,
+                        checkpoint.TimestampUtc.AddSeconds(-5),
+                        checkpoint.TimestampUtc,
+                        SummarizeWindow(frames.Where(frame =>
+                            frame.TimestampUtc >= checkpoint.TimestampUtc.AddSeconds(-5)
+                            && frame.TimestampUtc <= checkpoint.TimestampUtc)),
+                        checkpoint.ProcessAllocationRateBytesPerSecond))
+                    .ToArray(),
+                PortalWindows: portals.Select(portal =>
+                    new PortalWindowSummary(
+                        portal.Destination,
+                        portal.TimestampUtc,
+                        SummarizeWindow(frames.Where(frame =>
+                            frame.TimestampUtc >= portal.TimestampUtc.AddSeconds(-10)
+                            && frame.TimestampUtc <= portal.TimestampUtc.AddSeconds(5))),
+                        frames.Where(frame =>
+                                frame.TimestampUtc >= portal.TimestampUtc.AddSeconds(-10)
+                                && frame.TimestampUtc <= portal.TimestampUtc.AddSeconds(5))
+                            .OrderByDescending(frame => frame.CpuUs)
+                            .Take(20)
+                            .Select(frame => new WorstFrame(
+                                frame.Frame,
+                                Math.Round(
+                                    (frame.TimestampUtc - portal.TimestampUtc).TotalMilliseconds,
+                                    3),
+                                frame.CpuUs,
+                                frame.GpuUs,
+                                frame.AllocBytes,
+                                frame.UpdateUs,
+                                frame.UploadUs,
+                                frame.PacingUs))
+                            .ToArray()))
+                    .ToArray());
+
+            string output = Path.GetFullPath(args[3]);
+            Directory.CreateDirectory(
+                Path.GetDirectoryName(output)
+                ?? throw new InvalidOperationException("Output path has no directory."));
+            File.WriteAllText(output, JsonSerializer.Serialize(summary, JsonOptions));
+            Console.WriteLine($"wrote frame-history summary: {output}");
+            return 0;
+        }
+        catch (Exception error)
+        {
+            Console.Error.WriteLine($"frame-history summary failed: {error.Message}");
+            return 1;
+        }
+    }
+
+    public static int CompareScreenshots(string[] args)
+    {
+        if (args.Length < 3)
+        {
+            Console.Error.WriteLine(
+                "usage: AcDream.Cli compare-screenshots "
+                + "<expected.png> <actual.png> <out.json> "
+                + "[channelTolerance=2] [maxDifferentFraction=0.001] [mask.png]");
+            return 2;
+        }
+
+        try
+        {
+            int tolerance = args.Length >= 4
+                ? int.Parse(args[3], CultureInfo.InvariantCulture)
+                : 2;
+            double maxDifferentFraction = args.Length >= 5
+                ? double.Parse(args[4], CultureInfo.InvariantCulture)
+                : 0.001;
+            string? maskPath = args.Length >= 6 ? args[5] : null;
+            ScreenshotComparison comparison = CompareImages(
+                args[0],
+                args[1],
+                tolerance,
+                maxDifferentFraction,
+                maskPath);
+
+            string output = Path.GetFullPath(args[2]);
+            Directory.CreateDirectory(
+                Path.GetDirectoryName(output)
+                ?? throw new InvalidOperationException("Output path has no directory."));
+            File.WriteAllText(output, JsonSerializer.Serialize(comparison, JsonOptions));
+            Console.WriteLine(
+                $"screenshot comparison {(comparison.Passed ? "passed" : "failed")}: "
+                + $"{comparison.DifferentPixelFraction:P6} different");
+            return comparison.Passed ? 0 : 1;
+        }
+        catch (Exception error)
+        {
+            Console.Error.WriteLine($"screenshot comparison failed: {error.Message}");
+            return 1;
+        }
+    }
+
+    public static ScreenshotComparison CompareImages(
+        string expectedPath,
+        string actualPath,
+        int channelTolerance,
+        double maxDifferentFraction,
+        string? maskPath = null)
+    {
+        if ((uint)channelTolerance > byte.MaxValue)
+            throw new ArgumentOutOfRangeException(nameof(channelTolerance));
+        if (maxDifferentFraction is < 0 or > 1 || double.IsNaN(maxDifferentFraction))
+            throw new ArgumentOutOfRangeException(nameof(maxDifferentFraction));
+
+        using Image<Rgba32> expected = Image.Load<Rgba32>(expectedPath);
+        using Image<Rgba32> actual = Image.Load<Rgba32>(actualPath);
+        using Image<Rgba32>? mask = maskPath is null
+            ? null
+            : Image.Load<Rgba32>(maskPath);
+
+        if (expected.Width != actual.Width || expected.Height != actual.Height)
+        {
+            return new ScreenshotComparison(
+                Passed: false,
+                Width: actual.Width,
+                Height: actual.Height,
+                ExpectedWidth: expected.Width,
+                ExpectedHeight: expected.Height,
+                ChannelTolerance: channelTolerance,
+                MaxDifferentPixelFraction: maxDifferentFraction,
+                ComparedPixels: 0,
+                MaskedPixels: 0,
+                DifferentPixels: 0,
+                DifferentPixelFraction: 1,
+                MaximumChannelDelta: byte.MaxValue,
+                MeanAbsoluteChannelDelta: 0,
+                RootMeanSquareChannelDelta: 0,
+                ExpectedPath: Path.GetFileName(expectedPath),
+                ActualPath: Path.GetFileName(actualPath),
+                MaskPath: maskPath is null ? null : Path.GetFileName(maskPath));
+        }
+
+        if (mask is not null
+            && (mask.Width != expected.Width || mask.Height != expected.Height))
+        {
+            throw new InvalidDataException(
+                "Screenshot mask dimensions must match the compared images.");
+        }
+
+        long comparedPixels = 0;
+        long maskedPixels = 0;
+        long differentPixels = 0;
+        long absoluteDeltaSum = 0;
+        long squaredDeltaSum = 0;
+        int maximumDelta = 0;
+
+        for (int y = 0; y < expected.Height; y++)
+        {
+            for (int x = 0; x < expected.Width; x++)
+            {
+                if (mask is not null && mask[x, y].A != 0)
+                {
+                    maskedPixels++;
+                    continue;
+                }
+
+                comparedPixels++;
+                Rgba32 left = expected[x, y];
+                Rgba32 right = actual[x, y];
+                int redDelta = Math.Abs(left.R - right.R);
+                int greenDelta = Math.Abs(left.G - right.G);
+                int blueDelta = Math.Abs(left.B - right.B);
+                int alphaDelta = Math.Abs(left.A - right.A);
+
+                absoluteDeltaSum += redDelta + greenDelta + blueDelta + alphaDelta;
+                squaredDeltaSum +=
+                    redDelta * redDelta
+                    + greenDelta * greenDelta
+                    + blueDelta * blueDelta
+                    + alphaDelta * alphaDelta;
+                maximumDelta = Math.Max(
+                    maximumDelta,
+                    Math.Max(
+                        Math.Max(redDelta, greenDelta),
+                        Math.Max(blueDelta, alphaDelta)));
+                bool different =
+                    redDelta > channelTolerance
+                    || greenDelta > channelTolerance
+                    || blueDelta > channelTolerance
+                    || alphaDelta > channelTolerance;
+
+                if (different)
+                    differentPixels++;
+            }
+        }
+
+        double differingFraction = comparedPixels == 0
+            ? throw new InvalidDataException(
+                "Screenshot mask excludes every pixel; no comparison is possible.")
+            : differentPixels / (double)comparedPixels;
+        long comparedChannels = comparedPixels * 4;
+        return new ScreenshotComparison(
+            Passed: differingFraction <= maxDifferentFraction,
+            Width: actual.Width,
+            Height: actual.Height,
+            ExpectedWidth: expected.Width,
+            ExpectedHeight: expected.Height,
+            ChannelTolerance: channelTolerance,
+            MaxDifferentPixelFraction: maxDifferentFraction,
+            ComparedPixels: comparedPixels,
+            MaskedPixels: maskedPixels,
+            DifferentPixels: differentPixels,
+            DifferentPixelFraction: differingFraction,
+            MaximumChannelDelta: maximumDelta,
+            MeanAbsoluteChannelDelta: comparedChannels == 0
+                ? 0
+                : absoluteDeltaSum / (double)comparedChannels,
+            RootMeanSquareChannelDelta: comparedChannels == 0
+                ? 0
+                : Math.Sqrt(squaredDeltaSum / (double)comparedChannels),
+            ExpectedPath: Path.GetFileName(expectedPath),
+            ActualPath: Path.GetFileName(actualPath),
+            MaskPath: maskPath is null ? null : Path.GetFileName(maskPath));
+    }
+
+    private static IReadOnlyList<FrameRow> ReadFrames(string path)
+    {
+        string[] lines = File.ReadAllLines(path);
+        if (lines.Length == 0)
+            throw new InvalidDataException("Frame-history CSV is empty.");
+
+        string[] header = lines[0].Split(',');
+        var columns = header
+            .Select((name, index) => (name, index))
+            .ToDictionary(pair => pair.name, pair => pair.index, StringComparer.Ordinal);
+        string[] required =
+        [
+            "frame", "timestamp_utc", "cpu_us", "gpu_us", "alloc_bytes",
+            "update_us", "upload_us", "imgui_us", "pacing_us",
+        ];
+        foreach (string name in required)
+        {
+            if (!columns.ContainsKey(name))
+                throw new InvalidDataException($"Frame-history CSV is missing '{name}'.");
+        }
+
+        var rows = new List<FrameRow>(lines.Length - 1);
+        for (int lineNumber = 1; lineNumber < lines.Length; lineNumber++)
+        {
+            if (string.IsNullOrWhiteSpace(lines[lineNumber]))
+                continue;
+            string[] values = lines[lineNumber].Split(',');
+            try
+            {
+                rows.Add(new FrameRow(
+                    ParseInt(values, columns, "frame"),
+                    DateTime.Parse(
+                        values[columns["timestamp_utc"]],
+                        CultureInfo.InvariantCulture,
+                        DateTimeStyles.AdjustToUniversal | DateTimeStyles.AssumeUniversal),
+                    ParseLong(values, columns, "cpu_us"),
+                    ParseLong(values, columns, "gpu_us"),
+                    ParseLong(values, columns, "alloc_bytes"),
+                    ParseLong(values, columns, "update_us"),
+                    ParseLong(values, columns, "upload_us"),
+                    ParseLong(values, columns, "imgui_us"),
+                    ParseLong(values, columns, "pacing_us")));
+            }
+            catch (Exception error) when (
+                error is FormatException
+                or IndexOutOfRangeException
+                or KeyNotFoundException)
+            {
+                throw new InvalidDataException(
+                    $"Invalid frame-history row {lineNumber + 1}: {error.Message}",
+                    error);
+            }
+        }
+
+        return rows;
+    }
+
+    private static IReadOnlyList<CheckpointRow> ReadCheckpoints(string path)
+    {
+        var rows = new List<CheckpointRow>();
+        CheckpointRaw? previous = null;
+        foreach (string line in File.ReadLines(path))
+        {
+            if (string.IsNullOrWhiteSpace(line))
+                continue;
+            using JsonDocument document = JsonDocument.Parse(line);
+            JsonElement root = document.RootElement;
+            JsonElement resources = root.GetProperty("resources");
+            var current = new CheckpointRaw(
+                root.GetProperty("name").GetString()
+                    ?? throw new InvalidDataException("Checkpoint name is null."),
+                root.GetProperty("timestampUtc").GetDateTime().ToUniversalTime(),
+                resources.GetProperty("processTotalAllocatedBytes").GetInt64());
+            double? allocationRate = null;
+            if (previous is not null)
+            {
+                double seconds = (current.TimestampUtc - previous.TimestampUtc).TotalSeconds;
+                if (seconds > 0)
+                {
+                    allocationRate = Math.Max(
+                        0,
+                        current.ProcessAllocatedBytes - previous.ProcessAllocatedBytes)
+                        / seconds;
+                }
+            }
+
+            rows.Add(new CheckpointRow(
+                current.Name,
+                current.TimestampUtc,
+                allocationRate));
+            previous = current;
+        }
+
+        return rows;
+    }
+
+    private static IReadOnlyList<PortalMarker> ReadPortalMarkers(string path)
+    {
+        var markers = new List<PortalMarker>();
+        foreach (string line in File.ReadLines(path))
+        {
+            Match match = PortalMarkerPattern().Match(line);
+            if (!match.Success)
+                continue;
+            markers.Add(new PortalMarker(
+                DateTime.Parse(
+                    match.Groups["timestamp"].Value,
+                    CultureInfo.InvariantCulture,
+                    DateTimeStyles.AdjustToUniversal | DateTimeStyles.AssumeUniversal),
+                match.Groups["destination"].Value));
+        }
+
+        return markers;
+    }
+
+    private static WindowSummary SummarizeWindow(IEnumerable<FrameRow> source)
+    {
+        FrameRow[] rows = source.OrderBy(row => row.TimestampUtc).ToArray();
+        return new WindowSummary(
+            FrameCount: rows.Length,
+            DurationSeconds: rows.Length < 2
+                ? 0
+                : (rows[^1].TimestampUtc - rows[0].TimestampUtc).TotalSeconds,
+            CpuUs: SummarizeMetric(rows.Select(row => row.CpuUs)),
+            GpuUs: SummarizeMetric(rows.Where(row => row.GpuUs >= 0).Select(row => row.GpuUs)),
+            AllocationBytes: SummarizeMetric(rows.Select(row => row.AllocBytes)),
+            UpdateUs: SummarizeMetric(rows.Select(row => row.UpdateUs)),
+            UploadUs: SummarizeMetric(rows.Select(row => row.UploadUs)),
+            ImGuiUs: SummarizeMetric(rows.Select(row => row.ImGuiUs)),
+            PacingUs: SummarizeMetric(rows.Select(row => row.PacingUs)),
+            TotalPositiveAllocationBytes: rows.Sum(row => Math.Max(0, row.AllocBytes)),
+            CpuStandardDeviationUs: StandardDeviation(rows.Select(row => row.CpuUs)));
+    }
+
+    private static MetricSummary SummarizeMetric(IEnumerable<long> source)
+    {
+        long[] values = source.Order().ToArray();
+        if (values.Length == 0)
+            return new MetricSummary(0, 0, 0, 0, 0, 0, 0);
+        return new MetricSummary(
+            values.Length,
+            Percentile(values, 0.50),
+            Percentile(values, 0.95),
+            Percentile(values, 0.99),
+            Percentile(values, 0.999),
+            values[^1],
+            values.Average());
+    }
+
+    private static long Percentile(long[] sorted, double percentile)
+    {
+        int index = (int)Math.Ceiling(sorted.Length * percentile) - 1;
+        return sorted[Math.Clamp(index, 0, sorted.Length - 1)];
+    }
+
+    private static double StandardDeviation(IEnumerable<long> source)
+    {
+        long[] values = source.ToArray();
+        if (values.Length == 0)
+            return 0;
+        double average = values.Average();
+        double variance = values.Sum(value => Math.Pow(value - average, 2)) / values.Length;
+        return Math.Sqrt(variance);
+    }
+
+    private static int ParseInt(
+        string[] values,
+        IReadOnlyDictionary<string, int> columns,
+        string name) =>
+        int.Parse(values[columns[name]], CultureInfo.InvariantCulture);
+
+    private static long ParseLong(
+        string[] values,
+        IReadOnlyDictionary<string, int> columns,
+        string name) =>
+        long.Parse(values[columns[name]], CultureInfo.InvariantCulture);
+
+    [GeneratedRegex(
+        "^(?<timestamp>\\S+) materialized destination='(?<destination>[^']+)'",
+        RegexOptions.CultureInvariant)]
+    private static partial Regex PortalMarkerPattern();
+
+    private sealed record FrameRow(
+        int Frame,
+        DateTime TimestampUtc,
+        long CpuUs,
+        long GpuUs,
+        long AllocBytes,
+        long UpdateUs,
+        long UploadUs,
+        long ImGuiUs,
+        long PacingUs);
+
+    private sealed record CheckpointRaw(
+        string Name,
+        DateTime TimestampUtc,
+        long ProcessAllocatedBytes);
+
+    private sealed record CheckpointRow(
+        string Name,
+        DateTime TimestampUtc,
+        double? ProcessAllocationRateBytesPerSecond);
+
+    private sealed record PortalMarker(DateTime TimestampUtc, string Destination);
+}
+
+public sealed record MetricSummary(
+    int Count,
+    long P50,
+    long P95,
+    long P99,
+    long P999,
+    long Maximum,
+    double Mean);
+
+public sealed record WindowSummary(
+    int FrameCount,
+    double DurationSeconds,
+    MetricSummary CpuUs,
+    MetricSummary GpuUs,
+    MetricSummary AllocationBytes,
+    MetricSummary UpdateUs,
+    MetricSummary UploadUs,
+    MetricSummary ImGuiUs,
+    MetricSummary PacingUs,
+    long TotalPositiveAllocationBytes,
+    double CpuStandardDeviationUs);
+
+public sealed record NamedWindowSummary(
+    string Name,
+    DateTime StartUtc,
+    DateTime EndUtc,
+    WindowSummary Metrics,
+    double? ProcessAllocationRateBytesPerSecond);
+
+public sealed record WorstFrame(
+    int Frame,
+    double RelativeToMaterializationMs,
+    long CpuUs,
+    long GpuUs,
+    long AllocationBytes,
+    long UpdateUs,
+    long UploadUs,
+    long PacingUs);
+
+public sealed record PortalWindowSummary(
+    string Destination,
+    DateTime MaterializedUtc,
+    WindowSummary Metrics,
+    IReadOnlyList<WorstFrame> WorstFrames);
+
+public sealed record FrameHistoryReport(
+    string SourceFrameHistory,
+    int FrameCount,
+    DateTime? FirstFrameUtc,
+    DateTime? LastFrameUtc,
+    WindowSummary Route,
+    IReadOnlyList<NamedWindowSummary> CheckpointWindows,
+    IReadOnlyList<PortalWindowSummary> PortalWindows);
+
+public sealed record ScreenshotComparison(
+    bool Passed,
+    int Width,
+    int Height,
+    int ExpectedWidth,
+    int ExpectedHeight,
+    int ChannelTolerance,
+    double MaxDifferentPixelFraction,
+    long ComparedPixels,
+    long MaskedPixels,
+    long DifferentPixels,
+    double DifferentPixelFraction,
+    int MaximumChannelDelta,
+    double MeanAbsoluteChannelDelta,
+    double RootMeanSquareChannelDelta,
+    string ExpectedPath,
+    string ActualPath,
+    string? MaskPath);

src/AcDream.Cli/Program.cs

@@ -8,6 +8,16 @@ using DatReaderWriter.Types;
 using Env = System.Environment;
 
 // ─── subcommand dispatch ────────────────────────────────────────────────────
+if (args.Length >= 1 && args[0] == "summarize-frame-history")
+{
+    return PerformanceTools.SummarizeFrameHistory(args[1..]);
+}
+
+if (args.Length >= 1 && args[0] == "compare-screenshots")
+{
+    return PerformanceTools.CompareScreenshots(args[1..]);
+}
+
 if (args.Length >= 1 && args[0] == "dump-vitals-bars")
 {
     string? dvbDatDir = args.ElementAtOrDefault(1) ?? Env.GetEnvironmentVariable("ACDREAM_DAT_DIR");

tests/AcDream.App.Tests/Diagnostics/ConnectedR6SoakContractTests.cs

@@ -18,10 +18,11 @@ public sealed class ConnectedR6SoakContractTests
     [Fact]
     public void RouteContainsExactlyNineOrderedCheckpointBarriers()
     {
-        string[] checkpoints = File.ReadAllLines(Path.Combine(
-                FindRepoRoot(),
-                "tools",
-                "connected-r6-soak.route.txt"))
+        string routePath = Path.Combine(
+            FindRepoRoot(),
+            "tools",
+            "connected-r6-soak.route.txt");
+        string[] checkpoints = File.ReadAllLines(routePath)
             .Select(static line => line.Trim())
             .Where(static line => line.StartsWith(
                 "checkpoint ",
@@ -31,10 +32,7 @@ public sealed class ConnectedR6SoakContractTests
 
         Assert.Equal(ExpectedCheckpointNames, checkpoints);
 
-        string[] teleports = File.ReadAllLines(Path.Combine(
-                FindRepoRoot(),
-                "tools",
-                "connected-r6-soak.route.txt"))
+        string[] teleports = File.ReadAllLines(routePath)
             .Select(static line => line.Trim())
             .Where(static line => line.StartsWith(
                 "command /teleloc ",
@@ -45,6 +43,97 @@ public sealed class ConnectedR6SoakContractTests
             " 1 0 0 0",
             line,
             StringComparison.Ordinal));
+
+        string[] screenshots = File.ReadAllLines(routePath)
+            .Select(static line => line.Trim())
+            .Where(static line => line.StartsWith(
+                "screenshot ",
+                StringComparison.Ordinal))
+            .Select(static line => line.Split(' ', StringSplitOptions.RemoveEmptyEntries)[1])
+            .ToArray();
+        Assert.Equal(ExpectedCheckpointNames, screenshots);
+    }
+
+    [Fact]
+    public void DenseTownRoutePinsArwicViewAndScreenshot()
+    {
+        string[] route = File.ReadAllLines(Path.Combine(
+                FindRepoRoot(),
+                "tools",
+                "connected-dense-town.route.txt"))
+            .Select(static line => line.Trim())
+            .Where(static line => line.Length > 0 && !line.StartsWith('#'))
+            .ToArray();
+
+        AssertAppearsInOrder(
+            string.Join('\n', route),
+            "command /telepoi Arwic",
+            "wait materialized 1 60000",
+            "input down MovementTurnRight",
+            "sleep 6000",
+            "input up MovementTurnRight",
+            "screenshot arwic-dense 10000",
+            "checkpoint arwic-dense");
+    }
+
+    [Fact]
+    public void PerformanceRoutesPinNoonBeforeTheirFirstTeleport()
+    {
+        foreach (string routeName in new[]
+        {
+            "connected-r6-soak.route.txt",
+            "connected-dense-town.route.txt",
+        })
+        {
+            string source = File.ReadAllText(Path.Combine(
+                FindRepoRoot(),
+                "tools",
+                routeName));
+            int firstTeleport = source.IndexOf("command /tele", StringComparison.Ordinal);
+            Assert.True(firstTeleport > 0, $"{routeName} has no teleport command.");
+            string preTeleport = source[..firstTeleport];
+            Assert.Equal(
+                3,
+                CountOccurrences(
+                    preTeleport,
+                    "input press AcdreamCycleTimeOfDay"));
+        }
+    }
+
+    [Fact]
+    public void ReferenceConfigurationDefinesLocalAuthorityAndScreenshotRule()
+    {
+        string source = File.ReadAllText(Path.Combine(
+            FindRepoRoot(),
+            "docs",
+            "research",
+            "2026-07-24-performance-reference-configuration.json"));
+        using System.Text.Json.JsonDocument document =
+            System.Text.Json.JsonDocument.Parse(source);
+        System.Text.Json.JsonElement root = document.RootElement;
+
+        Assert.Equal(
+            "performance-gate",
+            root.GetProperty("displayPaths")
+                .GetProperty("authoritativeLocal")
+                .GetProperty("authority")
+                .GetString());
+        Assert.Equal(
+            "diagnostic-only",
+            root.GetProperty("displayPaths")
+                .GetProperty("diagnosticRdp")
+                .GetProperty("authority")
+                .GetString());
+        Assert.Equal(
+            2,
+            root.GetProperty("screenshotComparison")
+                .GetProperty("channelTolerance")
+                .GetInt32());
+        Assert.Equal(
+            0.001,
+            root.GetProperty("screenshotComparison")
+                .GetProperty("maxDifferentPixelFraction")
+                .GetDouble());
     }
 
     [Fact]
@@ -178,11 +267,102 @@ public sealed class ConnectedR6SoakContractTests
             "EnvDisclosure = Join-Path $artifactDir 'env-disclosure.json'",
             source,
             StringComparison.Ordinal);
+        Assert.Contains(
+            "$sensitive = $_.Name -match '(?i)(PASS|PASSWORD|TOKEN|SECRET|KEY)'",
+            source,
+            StringComparison.Ordinal);
+        Assert.Contains(
+            "Value = if ($sensitive) { '<redacted>' } else { $_.Value }",
+            source,
+            StringComparison.Ordinal);
         // ACDREAM_DUMP_MOVE_TRUTH stays SET (the exercise gate greps its
         // output) — it is now disclosed, not removed.
         Assert.Contains("$env:ACDREAM_DUMP_MOVE_TRUTH = '1'", source, StringComparison.Ordinal);
     }
 
+    [Fact]
+    public void SoakExportsAndSummarizesFrameHistory()
+    {
+        string source = File.ReadAllText(Path.Combine(
+            FindRepoRoot(),
+            "tools",
+            "run-connected-r6-soak.ps1"));
+
+        Assert.Contains(
+            "$env:ACDREAM_FRAME_HISTORY = $frameHistory",
+            source,
+            StringComparison.Ordinal);
+        AssertAppearsInOrder(
+            source,
+            "& dotnet $cliDll summarize-frame-history",
+            "$frameHistory",
+            "$checkpointTimeline",
+            "$markerLog",
+            "$frameSummary");
+        Assert.Contains("FrameHistory = $frameHistory", source, StringComparison.Ordinal);
+        Assert.Contains("FrameSummary = $frameSummary", source, StringComparison.Ordinal);
+    }
+
+    [Fact]
+    public void ContentionCaptureIsExplicitAndIncludesStackEvents()
+    {
+        string source = File.ReadAllText(Path.Combine(
+            FindRepoRoot(),
+            "tools",
+            "run-connected-r6-soak.ps1"));
+
+        Assert.Contains("[switch]$CaptureContention", source, StringComparison.Ordinal);
+        Assert.Contains(
+            "'Microsoft-Windows-DotNETRuntime:0x4000:5'",
+            source,
+            StringComparison.Ordinal);
+        Assert.Contains(
+            "ContentionTrace = if ($CaptureContention) { $contentionTrace } else { $null }",
+            source,
+            StringComparison.Ordinal);
+    }
+
+    [Fact]
+    public void RuntimeCountersCaptureProcessWideAllocationByDefault()
+    {
+        string source = File.ReadAllText(Path.Combine(
+            FindRepoRoot(),
+            "tools",
+            "run-connected-r6-soak.ps1"));
+
+        Assert.Contains("[switch]$SkipRuntimeCounters", source, StringComparison.Ordinal);
+        AssertAppearsInOrder(
+            source,
+            "if (-not $SkipRuntimeCounters) {",
+            "'--counters', 'System.Runtime'",
+            "'--refresh-interval', '1'",
+            "'--format', 'csv'",
+            "'--output', $runtimeCounters");
+        Assert.Contains(
+            "RuntimeCounters = if (-not $SkipRuntimeCounters) { $runtimeCounters } else { $null }",
+            source,
+            StringComparison.Ordinal);
+    }
+
+    [Fact]
+    public void DenseTownModeUsesTheDedicatedOneCheckpointRoute()
+    {
+        string source = File.ReadAllText(Path.Combine(
+            FindRepoRoot(),
+            "tools",
+            "run-connected-r6-soak.ps1"));
+
+        Assert.Contains("[switch]$DenseTown", source, StringComparison.Ordinal);
+        AssertAppearsInOrder(
+            source,
+            "if ($DenseTown) {",
+            "Name = 'Arwic dense'",
+            "$expectedCheckpointNames = @('arwic-dense')",
+            "$routeFileName = 'connected-dense-town.route.txt'",
+            "$runName = 'connected-dense-town'");
+        Assert.Contains("if (-not $DenseTown) {", source, StringComparison.Ordinal);
+    }
+
     private static int CountOccurrences(string source, string value)
     {
         int count = 0;

tests/AcDream.App.Tests/FrameProfilerReportTests.cs

@@ -20,18 +20,25 @@ public class FrameProfilerReportTests
         };
         var buffer = new StringWriter(CultureInfo.InvariantCulture);
 
-        FrameProfiler.WriteHistoryCsv(records, buffer);
+        FrameProfiler.WriteHistoryCsv(
+            records,
+            buffer,
+            new DateTime(2026, 7, 24, 10, 0, 0, DateTimeKind.Utc));
 
         string[] lines = buffer.ToString().Split(
             Environment.NewLine, StringSplitOptions.RemoveEmptyEntries);
         Assert.Equal(3, lines.Length);
         Assert.Equal(
-            "frame,timestamp_ms,cpu_us,gpu_us,alloc_bytes,update_us,upload_us,imgui_us,pacing_us",
+            "frame,timestamp_ms,timestamp_utc,cpu_us,gpu_us,alloc_bytes,update_us,upload_us,imgui_us,pacing_us",
             lines[0]);
-        Assert.Equal("0,12.500,1000,500,2048,100,200,30,40", lines[1]);
+        Assert.Equal(
+            "0,12.500,2026-07-24T10:00:00.0125000Z,1000,500,2048,100,200,30,40",
+            lines[1]);
         // gpu_us=-1 marks "no GPU sample available"; alloc_bytes can go
         // negative (documented alloc-channel behavior, matches FrameStatsBuffer.Max).
-        Assert.Equal("1,18.750,1200,-1,-256,110,210,31,41", lines[2]);
+        Assert.Equal(
+            "1,18.750,2026-07-24T10:00:00.0187500Z,1200,-1,-256,110,210,31,41",
+            lines[2]);
     }
 
 

tests/AcDream.App.Tests/Rendering/GameWindowRenderLeafCompositionTests.cs

@@ -182,8 +182,10 @@ public sealed class GameWindowRenderLeafCompositionTests
             "screenshotCaptured);");
         AssertAppearsInOrder(
             orchestrator,
-            "WorldRenderFrameOutcome world = _world.Render(input);",
+            "_gpuMeasurement.BeginFrame();",
+            "world = _world.Render(input);",
             "_presentation.Render(input, world);",
+            "_gpuMeasurement.EndFrame();",
             "new RenderFrameOutcome(world, presentation);",
             "_diagnostics.Publish(input, outcome);");
     }

tests/AcDream.App.Tests/Rendering/RenderFrameOrchestratorTests.cs

@@ -39,7 +39,8 @@ public sealed class RenderFrameOrchestratorTests
 
         Assert.Equal(
             [
-                "gpu-begin", "resources", "world", "presentation",
+                "gpu-begin", "measure-begin", "resources", "world", "presentation",
+                "measure-end",
                 "diagnostics", "post-diagnostics", "gpu-end",
             ],
             calls);
@@ -118,7 +119,8 @@ public sealed class RenderFrameOrchestratorTests
         Assert.Same(expected, actual);
         Assert.Equal(
             [
-                "gpu-begin", "resources", "world", "presentation",
+                "gpu-begin", "measure-begin", "resources", "world", "presentation",
+                "measure-end",
                 "diagnostics", "post-diagnostics", "gpu-end",
             ],
             calls);
@@ -177,7 +179,10 @@ public sealed class RenderFrameOrchestratorTests
         Assert.Same(renderFailure, actual.InnerExceptions[0]);
         Assert.Same(recoveryFailure, actual.InnerExceptions[1]);
         Assert.Equal(
-            ["gpu-begin", "resources", "world", "recovery-abort", "gpu-end"],
+            [
+                "gpu-begin", "measure-begin", "resources", "world",
+                "measure-end", "recovery-abort", "gpu-end",
+            ],
             calls);
     }
 
@@ -205,7 +210,8 @@ public sealed class RenderFrameOrchestratorTests
         Assert.Same(closeFailure, actual.InnerExceptions[2]);
         Assert.Equal(
             [
-                "gpu-begin", "resources", "world", "presentation",
+                "gpu-begin", "measure-begin", "resources", "world", "presentation",
+                "measure-end",
                 "recovery-abort", "gpu-end",
             ],
             calls);
@@ -217,19 +223,21 @@ public sealed class RenderFrameOrchestratorTests
         var phases = new RecordingPhases([]);
 
         Assert.Throws<ArgumentNullException>(() => new RenderFrameOrchestrator(
-            null!, phases, phases, phases, phases, phases, phases));
+            null!, phases, phases, phases, phases, phases, phases, phases));
         Assert.Throws<ArgumentNullException>(() => new RenderFrameOrchestrator(
-            phases, null!, phases, phases, phases, phases, phases));
+            phases, null!, phases, phases, phases, phases, phases, phases));
         Assert.Throws<ArgumentNullException>(() => new RenderFrameOrchestrator(
-            phases, phases, null!, phases, phases, phases, phases));
+            phases, phases, null!, phases, phases, phases, phases, phases));
         Assert.Throws<ArgumentNullException>(() => new RenderFrameOrchestrator(
-            phases, phases, phases, null!, phases, phases, phases));
+            phases, phases, phases, null!, phases, phases, phases, phases));
         Assert.Throws<ArgumentNullException>(() => new RenderFrameOrchestrator(
-            phases, phases, phases, phases, null!, phases, phases));
+            phases, phases, phases, phases, null!, phases, phases, phases));
         Assert.Throws<ArgumentNullException>(() => new RenderFrameOrchestrator(
-            phases, phases, phases, phases, phases, null!, phases));
+            phases, phases, phases, phases, phases, null!, phases, phases));
         Assert.Throws<ArgumentNullException>(() => new RenderFrameOrchestrator(
-            phases, phases, phases, phases, phases, phases, null!));
+            phases, phases, phases, phases, phases, phases, null!, phases));
+        Assert.Throws<ArgumentNullException>(() => new RenderFrameOrchestrator(
+            phases, phases, phases, phases, phases, phases, phases, null!));
     }
 
     [Fact]
@@ -238,6 +246,7 @@ public sealed class RenderFrameOrchestratorTests
         Type[] expectedFieldTypes =
         [
             typeof(IRenderFrameLifetime),
+            typeof(IRenderFrameGpuMeasurement),
             typeof(IRenderFrameResourcePhase),
             typeof(IWorldSceneFramePhase),
             typeof(IPrivatePresentationFramePhase),
@@ -308,22 +317,33 @@ public sealed class RenderFrameOrchestratorTests
 
     private static string[] ExpectedFailureCalls(string failurePoint) => failurePoint switch
     {
-        "resources" => ["gpu-begin", "resources", "recovery-abort", "gpu-end"],
-        "world" => ["gpu-begin", "resources", "world", "recovery-abort", "gpu-end"],
+        "resources" =>
+            [
+                "gpu-begin", "measure-begin", "resources", "measure-end",
+                "recovery-abort", "gpu-end",
+            ],
+        "world" =>
+            [
+                "gpu-begin", "measure-begin", "resources", "world", "measure-end",
+                "recovery-abort", "gpu-end",
+            ],
         "presentation" =>
             [
-                "gpu-begin", "resources", "world", "presentation",
+                "gpu-begin", "measure-begin", "resources", "world", "presentation",
+                "measure-end",
                 "recovery-abort", "gpu-end",
             ],
         "diagnostics" =>
             [
-                "gpu-begin", "resources", "world", "presentation", "diagnostics",
+                "gpu-begin", "measure-begin", "resources", "world", "presentation",
+                "measure-end", "diagnostics",
                 "recovery-abort", "gpu-end",
             ],
         "post-diagnostics" =>
             [
-                "gpu-begin", "resources", "world", "presentation", "diagnostics",
-                "post-diagnostics", "recovery-abort", "gpu-end",
+                "gpu-begin", "measure-begin", "resources", "world", "presentation",
+                "measure-end", "diagnostics", "post-diagnostics",
+                "recovery-abort", "gpu-end",
             ],
         _ => throw new ArgumentOutOfRangeException(nameof(failurePoint)),
     };
@@ -348,10 +368,11 @@ public sealed class RenderFrameOrchestratorTests
     }
 
     private static RenderFrameOrchestrator Create(RecordingPhases phases) =>
-        new(phases, phases, phases, phases, phases, phases, phases);
+        new(phases, phases, phases, phases, phases, phases, phases, phases);
 
     private sealed class RecordingPhases :
         IRenderFrameLifetime,
+        IRenderFrameGpuMeasurement,
         IRenderFrameResourcePhase,
         IWorldSceneFramePhase,
         IPrivatePresentationFramePhase,
@@ -376,15 +397,19 @@ public sealed class RenderFrameOrchestratorTests
         public WorldRenderFrameOutcome ObservedWorld { get; private set; }
         public RenderFrameOutcome ObservedOutcome { get; private set; }
 
-        public void BeginFrame() => Record("gpu-begin");
+        void IRenderFrameLifetime.BeginFrame() => Record("gpu-begin");
 
-        public void EndFrame()
+        void IRenderFrameLifetime.EndFrame()
         {
             _calls.Add("gpu-end");
             if (CloseFailure is not null)
                 throw CloseFailure;
         }
 
+        void IRenderFrameGpuMeasurement.BeginFrame() => Record("measure-begin");
+
+        void IRenderFrameGpuMeasurement.EndFrame() => _calls.Add("measure-end");
+
         public void AbortFrame()
         {
             _calls.Add("recovery-abort");

tests/AcDream.App.Tests/Rendering/RenderFrameRecoveryIntegrationTests.cs

@@ -33,6 +33,7 @@ public sealed class RenderFrameRecoveryIntegrationTests
             new Screenshots());
         var orchestrator = new RenderFrameOrchestrator(
             gpu,
+            new GpuMeasurement(),
             preparation,
             new World(failure),
             presentation,
@@ -87,6 +88,17 @@ public sealed class RenderFrameRecoveryIntegrationTests
         }
     }
 
+    private sealed class GpuMeasurement : IRenderFrameGpuMeasurement
+    {
+        public void BeginFrame()
+        {
+        }
+
+        public void EndFrame()
+        {
+        }
+    }
+
     private sealed class DevTools(FailureSwitch failure) : IDevToolsFrameLifecycle
     {
         public bool IsOpen { get; private set; }

tests/AcDream.App.Tests/Rendering/RenderFrameResourceControllerTests.cs

@@ -60,8 +60,8 @@ public sealed class RenderFrameResourceControllerTests
             "_uiText?.BeginFrame(gpuSlot);",
             "_clip?.BeginFrame(gpuSlot);",
             "_terrain?.BeginFrame(gpuSlot);",
-            "_lighting?.BeginFrame(gpuSlot);",
-            "_profiler.FrameBoundary(_gl);");
+            "_lighting?.BeginFrame(gpuSlot);");
+        Assert.DoesNotContain("_profiler.FrameBoundary(", source);
     }
 
     [Fact]

tests/AcDream.Cli.Tests/AcDream.Cli.Tests.csproj

@@ -0,0 +1,24 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <TargetFramework>net10.0</TargetFramework>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <Nullable>enable</Nullable>
+    <IsPackable>false</IsPackable>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.14.1" />
+    <PackageReference Include="xunit" Version="2.9.3" />
+    <PackageReference Include="xunit.runner.visualstudio" Version="3.1.4" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <Using Include="Xunit" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <ProjectReference Include="..\..\src\AcDream.Cli\AcDream.Cli.csproj" />
+  </ItemGroup>
+
+</Project>

tests/AcDream.Cli.Tests/PerformanceToolsTests.cs

@@ -0,0 +1,178 @@
+using System.Text.Json;
+using AcDream.Cli;
+using SixLabors.ImageSharp;
+using SixLabors.ImageSharp.PixelFormats;
+
+namespace AcDream.Cli.Tests;
+
+public sealed class PerformanceToolsTests
+{
+    [Fact]
+    public void CompareImages_AppliesChannelToleranceAndMask()
+    {
+        using var directory = new TemporaryDirectory();
+        string expectedPath = Path.Combine(directory.Path, "expected.png");
+        string actualPath = Path.Combine(directory.Path, "actual.png");
+        string maskPath = Path.Combine(directory.Path, "mask.png");
+
+        using (var expected = new Image<Rgba32>(2, 1))
+        using (var actual = new Image<Rgba32>(2, 1))
+        using (var mask = new Image<Rgba32>(2, 1))
+        {
+            expected[0, 0] = new Rgba32(10, 20, 30, 255);
+            expected[1, 0] = new Rgba32(40, 50, 60, 255);
+            actual[0, 0] = new Rgba32(12, 20, 30, 255);
+            actual[1, 0] = new Rgba32(200, 50, 60, 255);
+            mask[1, 0] = new Rgba32(0, 0, 0, 255);
+            expected.SaveAsPng(expectedPath);
+            actual.SaveAsPng(actualPath);
+            mask.SaveAsPng(maskPath);
+        }
+
+        ScreenshotComparison unmasked = PerformanceTools.CompareImages(
+            expectedPath,
+            actualPath,
+            channelTolerance: 2,
+            maxDifferentFraction: 0);
+        ScreenshotComparison masked = PerformanceTools.CompareImages(
+            expectedPath,
+            actualPath,
+            channelTolerance: 2,
+            maxDifferentFraction: 0,
+            maskPath);
+
+        Assert.False(unmasked.Passed);
+        Assert.Equal(1, unmasked.DifferentPixels);
+        Assert.True(masked.Passed);
+        Assert.Equal(1, masked.ComparedPixels);
+        Assert.Equal(1, masked.MaskedPixels);
+        Assert.Equal(0, masked.DifferentPixels);
+    }
+
+    [Fact]
+    public void CompareImages_RejectsAFullyMaskedComparison()
+    {
+        using var directory = new TemporaryDirectory();
+        string expectedPath = Path.Combine(directory.Path, "expected.png");
+        string actualPath = Path.Combine(directory.Path, "actual.png");
+        string maskPath = Path.Combine(directory.Path, "mask.png");
+        using (var image = new Image<Rgba32>(1, 1))
+        using (var mask = new Image<Rgba32>(1, 1))
+        {
+            mask[0, 0] = new Rgba32(0, 0, 0, 255);
+            image.SaveAsPng(expectedPath);
+            image.SaveAsPng(actualPath);
+            mask.SaveAsPng(maskPath);
+        }
+
+        InvalidDataException error = Assert.Throws<InvalidDataException>(() =>
+            PerformanceTools.CompareImages(
+                expectedPath,
+                actualPath,
+                channelTolerance: 2,
+                maxDifferentFraction: 0.001,
+                maskPath));
+
+        Assert.Contains("excludes every pixel", error.Message);
+    }
+
+    [Fact]
+    public void CompareScreenshots_WritesSerializableDimensionMismatch()
+    {
+        using var directory = new TemporaryDirectory();
+        string expectedPath = Path.Combine(directory.Path, "expected.png");
+        string actualPath = Path.Combine(directory.Path, "actual.png");
+        string outputPath = Path.Combine(directory.Path, "comparison.json");
+        using (var expected = new Image<Rgba32>(1, 1))
+        using (var actual = new Image<Rgba32>(2, 1))
+        {
+            expected.SaveAsPng(expectedPath);
+            actual.SaveAsPng(actualPath);
+        }
+
+        int exitCode = PerformanceTools.CompareScreenshots(
+            [expectedPath, actualPath, outputPath]);
+
+        Assert.Equal(1, exitCode);
+        using JsonDocument report = JsonDocument.Parse(File.ReadAllText(outputPath));
+        Assert.False(report.RootElement.GetProperty("passed").GetBoolean());
+        Assert.Equal("expected.png", report.RootElement.GetProperty("expectedPath").GetString());
+        Assert.Equal("actual.png", report.RootElement.GetProperty("actualPath").GetString());
+    }
+
+    [Fact]
+    public void SummarizeFrameHistory_WritesRouteCheckpointAndPortalPopulations()
+    {
+        using var directory = new TemporaryDirectory();
+        string framesPath = Path.Combine(directory.Path, "frames.csv");
+        string checkpointsPath = Path.Combine(directory.Path, "checkpoints.jsonl");
+        string markersPath = Path.Combine(directory.Path, "markers.log");
+        string outputPath = Path.Combine(directory.Path, "summary.json");
+
+        File.WriteAllLines(framesPath,
+        [
+            "frame,timestamp_ms,timestamp_utc,cpu_us,gpu_us,alloc_bytes,update_us,upload_us,imgui_us,pacing_us",
+            "0,0.000,2026-07-24T10:00:00.0000000Z,1000,500,100,100,10,0,0",
+            "1,1000.000,2026-07-24T10:00:01.0000000Z,2000,600,200,200,20,0,0",
+            "2,2000.000,2026-07-24T10:00:02.0000000Z,9000,700,300,300,30,0,0",
+        ]);
+        File.WriteAllText(
+            checkpointsPath,
+            """
+            {"name":"baseline","timestampUtc":"2026-07-24T10:00:01Z","resources":{"processTotalAllocatedBytes":1000}}
+            {"name":"return","timestampUtc":"2026-07-24T10:00:02Z","resources":{"processTotalAllocatedBytes":5000}}
+
+            """);
+        File.WriteAllText(
+            markersPath,
+            "2026-07-24T10:00:01.0000000Z materialized destination='Arwic' occurrence=1 elapsed=1.0s");
+
+        int exitCode = PerformanceTools.SummarizeFrameHistory(
+            [framesPath, checkpointsPath, markersPath, outputPath]);
+
+        Assert.Equal(0, exitCode);
+        using JsonDocument report = JsonDocument.Parse(File.ReadAllText(outputPath));
+        JsonElement root = report.RootElement;
+        Assert.Equal(3, root.GetProperty("frameCount").GetInt32());
+        Assert.Equal(
+            9000,
+            root.GetProperty("route").GetProperty("cpuUs").GetProperty("p99").GetInt64());
+        Assert.Equal(
+            2,
+            root.GetProperty("checkpointWindows").GetArrayLength());
+        Assert.Equal(
+            4000,
+            root.GetProperty("checkpointWindows")[1]
+                .GetProperty("processAllocationRateBytesPerSecond")
+                .GetDouble());
+        Assert.Equal(
+            "Arwic",
+            root.GetProperty("portalWindows")[0].GetProperty("destination").GetString());
+        Assert.Equal(
+            9000,
+            root.GetProperty("portalWindows")[0]
+                .GetProperty("worstFrames")[0]
+                .GetProperty("cpuUs")
+                .GetInt64());
+    }
+
+    private sealed class TemporaryDirectory : IDisposable
+    {
+        public TemporaryDirectory()
+        {
+            Path = System.IO.Path.Combine(
+                System.IO.Path.GetTempPath(),
+                "acdream-cli-tests",
+                Guid.NewGuid().ToString("N"));
+            Directory.CreateDirectory(Path);
+        }
+
+        public string Path { get; }
+
+        public void Dispose()
+        {
+            if (Directory.Exists(Path))
+                Directory.Delete(Path, recursive: true);
+        }
+    }
+}

tools/connected-dense-town.route.txt

@@ -0,0 +1,19 @@
+# Deterministic dense-town performance scene. Arwic is the established
+# dense-town oracle used by the June and July renderer investigations.
+# /telepoi supplies ACE's canonical arrival position and heading. The fixed
+# six-second retail-input turn pins the view facing for every capture.
+
+sleep 15000
+# Pin the client-only world-time override at noon for reproducible screenshots.
+input press AcdreamCycleTimeOfDay
+input press AcdreamCycleTimeOfDay
+input press AcdreamCycleTimeOfDay
+command /telepoi Arwic
+wait materialized 1 60000
+sleep 8000
+input down MovementTurnRight
+sleep 6000
+input up MovementTurnRight
+sleep 26000
+screenshot arwic-dense 10000
+checkpoint arwic-dense

tools/connected-r6-soak.route.txt

@@ -3,6 +3,11 @@
 # remains deterministic when no RDP/interactive desktop is attached.
 
 sleep 15000
+# Pin the client-only world-time override at noon for reproducible screenshots.
+# The diagnostic action cycles: live -> 0.00 -> 0.25 -> 0.50.
+input press AcdreamCycleTimeOfDay
+input press AcdreamCycleTimeOfDay
+input press AcdreamCycleTimeOfDay
 
 # Caul baseline + local movement/jump/combat exercise. Every teleloc carries
 # the identity quaternion so each timed turn begins from the same heading.
@@ -41,6 +46,7 @@ input up MovementForward
 sleep 700
 input press CombatToggleCombat
 sleep 7400
+screenshot caul-baseline 10000
 checkpoint caul-baseline
 
 # Sawato baseline.
@@ -51,6 +57,7 @@ input down MovementTurnRight
 sleep 6000
 input up MovementTurnRight
 sleep 22000
+screenshot sawato-baseline 10000
 checkpoint sawato-baseline
 
 # Rynthid world-edge streaming.
@@ -61,6 +68,7 @@ input down MovementTurnRight
 sleep 6000
 input up MovementTurnRight
 sleep 22000
+screenshot rynthid 10000
 checkpoint rynthid
 
 # Aerlinthe dense island.
@@ -71,6 +79,7 @@ input down MovementTurnRight
 sleep 6000
 input up MovementTurnRight
 sleep 22000
+screenshot aerlinthe 10000
 checkpoint aerlinthe
 
 # Same-location lifecycle revisit.
@@ -81,6 +90,7 @@ input down MovementTurnRight
 sleep 6000
 input up MovementTurnRight
 sleep 22000
+screenshot sawato-return 10000
 checkpoint sawato-return
 
 # Holtburg mixed-town workload + local exercise.
@@ -119,6 +129,7 @@ input up MovementForward
 sleep 700
 input press CombatToggleCombat
 sleep 7400
+screenshot holtburg 10000
 checkpoint holtburg
 
 # Caul return/leak oracle + final local exercise.
@@ -157,6 +168,7 @@ input up MovementForward
 sleep 700
 input press CombatToggleCombat
 sleep 15000
+screenshot caul-return 10000
 checkpoint caul-return
 
 # A second warm-cache Sawato/Caul revisit is the plateau oracle. The first
@@ -170,6 +182,7 @@ input down MovementTurnRight
 sleep 6000
 input up MovementTurnRight
 sleep 22000
+screenshot sawato-plateau 10000
 checkpoint sawato-plateau
 
 command /teleloc 0xC95B0001 14.8 0.3 12.005 1 0 0 0
@@ -179,4 +192,5 @@ input down MovementTurnRight
 sleep 6000
 input up MovementTurnRight
 sleep 22000
+screenshot caul-plateau 10000
 checkpoint caul-plateau

tools/run-connected-r6-soak.ps1

@@ -5,6 +5,9 @@ param(
     [string]$Password = $env:ACDREAM_TEST_PASS,
     [switch]$SkipBuild,
     [switch]$Uncapped,
+    [switch]$DenseTown,
+    [switch]$CaptureContention,
+    [switch]$SkipRuntimeCounters,
     [int]$LoginTimeoutSeconds = 90
 )
 
@@ -14,33 +17,45 @@ $ErrorActionPreference = 'Stop'
 if ([string]::IsNullOrWhiteSpace($Account)) { $Account = 'testaccount' }
 if ([string]::IsNullOrWhiteSpace($Password)) { $Password = 'testpassword' }
 
-$destinations = @(
-    [pscustomobject]@{ Name = 'Caul'; Occurrence = 1; Exercise = $true },
-    [pscustomobject]@{ Name = 'Sawato'; Occurrence = 2; Exercise = $false },
-    [pscustomobject]@{ Name = 'Rynthid'; Occurrence = 3; Exercise = $false },
-    [pscustomobject]@{ Name = 'Aerlinthe'; Occurrence = 4; Exercise = $false },
-    [pscustomobject]@{ Name = 'Sawato revisit'; Occurrence = 5; Exercise = $false },
-    [pscustomobject]@{ Name = 'Holtburg'; Occurrence = 6; Exercise = $true },
-    [pscustomobject]@{ Name = 'Caul return'; Occurrence = 7; Exercise = $true },
-    [pscustomobject]@{ Name = 'Sawato plateau'; Occurrence = 8; Exercise = $false },
-    [pscustomobject]@{ Name = 'Caul plateau'; Occurrence = 9; Exercise = $false }
-)
-$expectedCheckpointNames = @(
-    'caul-baseline',
-    'sawato-baseline',
-    'rynthid',
-    'aerlinthe',
-    'sawato-return',
-    'holtburg',
-    'caul-return',
-    'sawato-plateau',
-    'caul-plateau'
-)
+if ($DenseTown) {
+    [object[]]$destinations = @(
+        [pscustomobject]@{ Name = 'Arwic dense'; Occurrence = 1; Exercise = $false }
+    )
+    [string[]]$expectedCheckpointNames = @('arwic-dense')
+    $routeFileName = 'connected-dense-town.route.txt'
+    $runName = 'connected-dense-town'
+}
+else {
+    [object[]]$destinations = @(
+        [pscustomobject]@{ Name = 'Caul'; Occurrence = 1; Exercise = $true },
+        [pscustomobject]@{ Name = 'Sawato'; Occurrence = 2; Exercise = $false },
+        [pscustomobject]@{ Name = 'Rynthid'; Occurrence = 3; Exercise = $false },
+        [pscustomobject]@{ Name = 'Aerlinthe'; Occurrence = 4; Exercise = $false },
+        [pscustomobject]@{ Name = 'Sawato revisit'; Occurrence = 5; Exercise = $false },
+        [pscustomobject]@{ Name = 'Holtburg'; Occurrence = 6; Exercise = $true },
+        [pscustomobject]@{ Name = 'Caul return'; Occurrence = 7; Exercise = $true },
+        [pscustomobject]@{ Name = 'Sawato plateau'; Occurrence = 8; Exercise = $false },
+        [pscustomobject]@{ Name = 'Caul plateau'; Occurrence = 9; Exercise = $false }
+    )
+    [string[]]$expectedCheckpointNames = @(
+        'caul-baseline',
+        'sawato-baseline',
+        'rynthid',
+        'aerlinthe',
+        'sawato-return',
+        'holtburg',
+        'caul-return',
+        'sawato-plateau',
+        'caul-plateau'
+    )
+    $routeFileName = 'connected-r6-soak.route.txt'
+    $runName = 'connected-r6-soak'
+}
 
 $stamp = Get-Date -Format 'yyyyMMdd-HHmmss'
 $logDir = Join-Path $Repository 'logs'
 $null = New-Item -ItemType Directory -Force -Path $logDir
-$prefix = Join-Path $logDir "connected-r6-soak-$stamp"
+$prefix = Join-Path $logDir "$runName-$stamp"
 $stdoutLog = "$prefix.out.log"
 $stderrLog = "$prefix.err.log"
 $markerLog = "$prefix.markers.log"
@@ -48,13 +63,24 @@ $sampleCsv = "$prefix.samples.csv"
 $reportJson = "$prefix.report.json"
 $artifactDir = "$prefix.artifacts"
 $checkpointTimeline = Join-Path $artifactDir 'world-lifecycle.checkpoints.jsonl'
-$routePath = Join-Path $Repository 'tools\connected-r6-soak.route.txt'
+$frameHistory = Join-Path $artifactDir 'frame-history.csv'
+$frameSummary = Join-Path $artifactDir 'frame-history-summary.json'
+$contentionTrace = Join-Path $artifactDir 'contention.nettrace'
+$contentionStdout = Join-Path $artifactDir 'contention.out.log'
+$contentionStderr = Join-Path $artifactDir 'contention.err.log'
+$runtimeCounters = Join-Path $artifactDir 'runtime-counters.csv'
+$counterStdout = Join-Path $artifactDir 'runtime-counters.out.log'
+$counterStderr = Join-Path $artifactDir 'runtime-counters.err.log'
+$routePath = Join-Path $Repository "tools\$routeFileName"
 $exe = Join-Path $Repository 'src\AcDream.App\bin\Release\net10.0\AcDream.App.exe'
+$cliDll = Join-Path $Repository 'src\AcDream.Cli\bin\Release\net10.0\AcDream.Cli.dll'
 
 $samples = [System.Collections.Generic.List[object]]::new()
 $failures = [System.Collections.Generic.List[string]]::new()
 $warnings = [System.Collections.Generic.List[string]]::new()
 $process = $null
+$traceProcess = $null
+$counterProcess = $null
 $stopwatch = [Diagnostics.Stopwatch]::StartNew()
 $gracefulExit = $false
 $exitCode = $null
@@ -374,6 +400,10 @@ function Add-CanonicalCheckpointFailures([Diagnostics.Process]$Client) {
         }
     }
 
+    if ($DenseTown) {
+        return
+    }
+
     $caulReturn = $canonicalCheckpoints |
         Where-Object { $_.name -eq 'caul-return' } |
         Select-Object -First 1
@@ -588,6 +618,7 @@ if (-not $SkipBuild) {
     if ($LASTEXITCODE -ne 0) { throw "Release build failed with exit code $LASTEXITCODE" }
 }
 if (-not (Test-Path -LiteralPath $exe)) { throw "client executable not found: $exe" }
+if (-not (Test-Path -LiteralPath $cliDll)) { throw "CLI assembly not found: $cliDll" }
 
 $commit = (& git -C $Repository rev-parse HEAD).Trim()
 $sourceStatus = @(& git -C $Repository status --short)
@@ -603,6 +634,7 @@ $env:ACDREAM_TEST_USER = $Account
 $env:ACDREAM_TEST_PASS = $Password
 $env:ACDREAM_RETAIL_UI = '1'
 $env:ACDREAM_FRAME_PROF = '1'
+$env:ACDREAM_FRAME_HISTORY = $frameHistory
 # Capped by default (matches the retail presentation cadence the connected
 # visual matrix is gated against); pass -Uncapped to opt into uncapped
 # render, matching run-connected-world-lifecycle-gate.ps1's pattern.
@@ -623,11 +655,21 @@ $env:ACDREAM_WB_DIAG = $null
 $null = New-Item -ItemType Directory -Force -Path $artifactDir
 $acdreamEnvVars = Get-ChildItem Env: | Where-Object { $_.Name -like 'ACDREAM_*' } |
     Sort-Object Name |
-    ForEach-Object { [pscustomobject]@{ Name = $_.Name; Value = $_.Value } }
+    ForEach-Object {
+        $sensitive = $_.Name -match '(?i)(PASS|PASSWORD|TOKEN|SECRET|KEY)'
+        [pscustomobject]@{
+            Name = $_.Name
+            Value = if ($sensitive) { '<redacted>' } else { $_.Value }
+        }
+    }
 $envDisclosure = [pscustomobject][ordered]@{
     Script = 'run-connected-r6-soak.ps1'
     GeneratedUtc = [DateTime]::UtcNow.ToString('O')
     Uncapped = [bool]$Uncapped
+    DenseTown = [bool]$DenseTown
+    CaptureContention = [bool]$CaptureContention
+    RuntimeCounters = -not [bool]$SkipRuntimeCounters
+    Route = $routeFileName
     EnvironmentVariables = @($acdreamEnvVars)
 }
 $envDisclosure | ConvertTo-Json -Depth 4 |
@@ -638,6 +680,42 @@ try {
         -RedirectStandardOutput $stdoutLog -RedirectStandardError $stderrLog -PassThru
     Write-Marker "launch pid=$($process.Id) commit=$commit session='$env:SESSIONNAME'"
 
+    if (-not $SkipRuntimeCounters) {
+        $counterArguments = @(
+            'collect',
+            '--process-id', $process.Id,
+            '--counters', 'System.Runtime',
+            '--refresh-interval', '1',
+            '--format', 'csv',
+            '--output', $runtimeCounters,
+            '--duration', '00:00:15:00'
+        )
+        $counterProcess = Start-Process -FilePath 'dotnet-counters' `
+            -ArgumentList $counterArguments `
+            -RedirectStandardOutput $counterStdout `
+            -RedirectStandardError $counterStderr `
+            -PassThru `
+            -WindowStyle Hidden
+        Write-Marker "runtime-counters pid=$($counterProcess.Id)"
+    }
+
+    if ($CaptureContention) {
+        $traceArguments = @(
+            'collect',
+            '--process-id', $process.Id,
+            '--providers', 'Microsoft-Windows-DotNETRuntime:0x4000:5',
+            '--output', $contentionTrace,
+            '--duration', '00:00:15:00'
+        )
+        $traceProcess = Start-Process -FilePath 'dotnet-trace' `
+            -ArgumentList $traceArguments `
+            -RedirectStandardOutput $contentionStdout `
+            -RedirectStandardError $contentionStderr `
+            -PassThru `
+            -WindowStyle Hidden
+        Write-Marker "contention-capture pid=$($traceProcess.Id)"
+    }
+
     $null = Wait-ForLogPattern $process $stdoutLog 'live: in world' 1 $LoginTimeoutSeconds
     $null = Wait-ForLogPattern $process $stdoutLog 'live: first player position' 1 $LoginTimeoutSeconds
     Write-Marker ("in-world elapsed={0:N1}s" -f $stopwatch.Elapsed.TotalSeconds)
@@ -681,15 +759,19 @@ try {
         $failures.Add("expected $($destinations.Count) teleport materializations")
     }
 
+    $lastCheckpointName = $expectedCheckpointNames[-1]
+    $lastCheckpointSequence = $expectedCheckpointNames.Count
     $null = Wait-ForLogPattern `
         $process `
         $stdoutLog `
-        '[world-gate] checkpoint name=caul-plateau sequence=9' `
+        "[world-gate] checkpoint name=$lastCheckpointName sequence=$lastCheckpointSequence" `
         1 `
         30
     $canonicalCheckpoints = @(Read-CanonicalCheckpoints)
     Add-CanonicalCheckpointFailures $process
-    Add-RelativeGateFailures
+    if (-not $DenseTown) {
+        Add-RelativeGateFailures
+    }
 
     Write-Marker 'route-complete requesting graceful close'
     $gracefulExit = Close-ClientGracefully $process
@@ -717,6 +799,46 @@ finally {
         if ($process.HasExited -and $null -eq $exitCode) { $exitCode = [int]$process.ExitCode }
         $process.Dispose()
     }
+    if ($null -ne $traceProcess) {
+        if (-not $traceProcess.WaitForExit(30000)) {
+            $warnings.Add('dotnet-trace did not exit within 30 seconds of client shutdown')
+            Stop-Process -Id $traceProcess.Id -Force
+            $traceProcess.WaitForExit(10000)
+        }
+        if (-not (Test-Path -LiteralPath $contentionTrace)) {
+            $failures.Add('contention capture did not produce a nettrace artifact')
+        }
+        $traceProcess.Dispose()
+    }
+    if ($null -ne $counterProcess) {
+        if (-not $counterProcess.WaitForExit(30000)) {
+            $warnings.Add('dotnet-counters did not exit within 30 seconds of client shutdown')
+            Stop-Process -Id $counterProcess.Id -Force
+            $counterProcess.WaitForExit(10000)
+        }
+        if (-not (Test-Path -LiteralPath $runtimeCounters)) {
+            $failures.Add('runtime counter capture did not produce a CSV artifact')
+        }
+        $counterProcess.Dispose()
+    }
+
+    if (-not (Test-Path -LiteralPath $frameHistory)) {
+        $failures.Add('frame-history export was not written during graceful shutdown')
+    }
+    elseif ((Test-Path -LiteralPath $checkpointTimeline) -and
+        (Test-Path -LiteralPath $markerLog)) {
+        & dotnet $cliDll summarize-frame-history `
+            $frameHistory `
+            $checkpointTimeline `
+            $markerLog `
+            $frameSummary
+        if ($LASTEXITCODE -ne 0) {
+            $failures.Add("frame-history summary failed with exit code $LASTEXITCODE")
+        }
+        elseif (-not (Test-Path -LiteralPath $frameSummary)) {
+            $failures.Add('frame-history summary did not produce its JSON artifact')
+        }
+    }
 
     $samples | Export-Csv -LiteralPath $sampleCsv -NoTypeInformation
     $report = [pscustomobject][ordered]@{
@@ -742,6 +864,10 @@ finally {
             ReportJson = $reportJson
             CheckpointTimeline = $checkpointTimeline
             EnvDisclosure = Join-Path $artifactDir 'env-disclosure.json'
+            FrameHistory = $frameHistory
+            FrameSummary = $frameSummary
+            ContentionTrace = if ($CaptureContention) { $contentionTrace } else { $null }
+            RuntimeCounters = if (-not $SkipRuntimeCounters) { $runtimeCounters } else { $null }
         }
     }
     $report | ConvertTo-Json -Depth 8 | Set-Content -LiteralPath $reportJson -Encoding utf8