Expose and package temporal rendering with guarded edge history

docs/manual/editor/diagnostics.md

@@ -12,6 +12,12 @@ On Windows, use `windows-debug` for both presets and `build/windows-debug/faset_
 
 Use the **Visibility** selector to compare **Direct**, **GPU frustum**, and **GPU occlusion** on the same open scene. This is a live renderer setting for the Editor viewport; it does not change the scene or exported game. The selected mode is independent of **Freeze counters**. The counters describe the previous completed frame, so render one more frame after changing modes before reading them. **Effective path** names the algorithm that actually ran. A **Fallback from** line appears when device or target capabilities prevent the selected mode; for example, GPU occlusion may use GPU frustum if HZB is unavailable.
 
+Use the **Temporal** selector for **Off**, **TAA**, or **Upscale**. Upscale shows a
+50–99% render-scale slider; output UI remains sharp. The requested/effective
+mode, fallback reason, internal extent, history reset reason and temporal GPU
+pass times are shown separately from visibility and HZB history. This selector
+only changes the live Editor viewport. See [Temporal rendering](temporal.md).
+
 The panel reports the previous completed frame: renderer wall time, GPU timestamp time where available, synchronous readback time, draw calls, packed vertices, culled meshes, textures, explicit Vulkan allocation sizes, actual validation availability/errors, and GPU pass-label count. It also shows whether GPU visibility ran, submitted indirect bins, visible instances, frustum rejects, deferred and post-pass visible instances, HZB history validity, counts per prepared LOD level, and GPU pass timings where available. GPU counts are explicitly marked unavailable until the first frame rendered with diagnostics open; only a displayed zero is a measured zero. **Previous HZB history: invalid** is expected after a camera cut or resize until compatible depth history is available. A current HZB preview can still exist after that first frame because it was built from the current depth. Renderer wall time includes waiting for GPU work; it is not thread CPU usage. Memory excludes driver-internal allocations. The overlay itself adds drawing work, so hide it for a baseline performance measurement.
 
 In **GPU occlusion** mode, enable **Show HZB** to inspect the current grayscale depth pyramid. The **Mip** slider selects a pyramid level; the preview starts at mip 3 to keep its readback small. A larger mip number shows coarser depth. The preview reads the HZB only while the panel and toggle are open, and only once per completed frame or mip change. Switching it off or closing the panel releases the preview; its GPU texture retires when the next frame begins. Opening diagnostics also enables readback of GPU visibility counters, which is disabled again when the panel closes. Disable the HZB preview for performance comparisons: its diagnostic copy and texture upload add GPU and CPU work. **Freeze counters** does not freeze the HZB image.