engine: presets E/F AutoExposure, the game's exposure fields and NGX's jitter order

NGX's CNN takes this frame's exposure scale and pre-exposure in both translated kernels (input words 244-256,
reconstruction 592-604) and the previous frame's exposure as the input kernel's texture 352
(cuda_copy_exposure_kernel's half surface). The runtime left all of it at the model dump's values, so HDR games
with a pre-exposure other than 1 or a changing exposure measured 18-39 dB against NGX; now 54-64 dB.

AutoExposure (flag 0x40), which the shim refused for E/F: NGX runs K's log-mean measurement on M's grid every
second frame. exposure_k.comp MODE 3 writes it to the 1x1 image the kernels sample; sr/exposure_copy_e.comp
keeps the previous exposure. 60-66 dB over eleven frames at 960x540 -> 1920x1080, pre-exposure 19-21.

The reconstruction's jitter words 544-556 are (y, x); the runtime wrote (-x, -y), which matches only the
harness's first three jitters, so every later frame of a game's jitter sequence measured 26-28 dB. Twelve-frame
captures now measure 60-66 dB HDR and LDR; on the Steam Deck through the shim 51-67 dB against ZLUDA.

The D3D12 harness takes per-frame lists in D4R_HARNESS_PRE_EXPOSURE / _EXPOSURE_SCALE; d4r-e takes the
AutoExposure flag, per-frame exposure values and the game's exposure texture. E/F models need rebuilding
(the install's model cache key changes); older models keep the old binding and refuse AutoExposure.

engine/README.md

@@ -1147,7 +1147,25 @@ in two constants.
   packed in the DLL; NGX uploads them unpacked), `runtime_e.inc` is `EModel` / `EEngine`, `game_e.cpp` the game
   adapter, `replay_e.cpp` the replay (`d4r-e`). The shim runs presets 5 and 6 with `engine\e` / `engine\f`
   (`D4R_ENGINE_MODEL_E_DIR`, `_F_DIR`), LDR or HDR, either motion resolution, any render size (a new size rebuilds
-  the engine); not with AutoExposure. `build-engine-models.sh` builds both.
+  the engine), the game's exposure texture or AutoExposure. `build-engine-models.sh` builds both.
+- Exposure (HDR; harness captures with per-frame pre-exposure, exposure scale and exposure texture schedules,
+  2026-10-19). Both translated kernels take this frame's exposure scale (twice), pre-exposure and 1 / pre-exposure
+  (input words 244-256, reconstruction 592-604). They sample the exposure as 1x1 textures: the input kernel's 344 and
+  360 and the reconstruction's 472 and 480 this frame's, the input kernel's 352 the previous frame's, which NGX's
+  `cuda_copy_exposure_kernel` copies into a half surface after each frame (the current one on a reset frame):
+  `sr/exposure_copy_e.comp`. With AutoExposure NGX runs K's measurement (`cuda_luma_convert_kernel`, three
+  `cuda_reduce_sum_kernel`, `cuda_auto_exposure_copy_kernel`: key 0.18 / 0.82 times exp(-mean log luma), the luma
+  scaled by 1 / pre-exposure, truncated to half) on every second frame from the first, on M's grid (half the output,
+  half the render size but at least 256 above 2x), and ignores the game's texture: `exposure_k.comp` MODE 3. The
+  engine used to leave all of this at the model dump's values (exposure 1, the current exposure as the previous one):
+  at 1280x720 -> 1920x1080 with pre-exposure 4/2/8 and scale 0.5/0.75/1.25 it measured 39/18/29 dB against NGX with
+  the game's texture, now 64/55/54 dB; with AutoExposure 65/54/54 dB, through the shim as through `d4r-e` (neutral
+  exposure: 64-66 dB, unchanged). Models built before this keep the old binding and refuse AutoExposure.
+- The reconstruction's jitter words 544-556 are the previous and this frame's jitter as (y, x). The runtime wrote
+  (-x, -y), which agrees only on the harness's first three jitters (0, -+0.25), so three-frame checks passed while
+  later frames of the jitter sequence measured 26-28 dB (every game's Halton jitter was affected). Twelve-frame
+  captures at 640x360 -> 1280x720 now measure 60-66 dB (HDR), 61-66 dB (LDR), and with AutoExposure at
+  960x540 -> 1920x1080 and pre-exposure 19-21 60-66 dB; on the Steam Deck through the shim 51-67 dB against ZLUDA.
 
 With the f32 reconstruction head, accuracy against NGX through ZLUDA (three temporal frames): 63-68 dB at 640x360 -> 1280x720
 (LDR and HDR, both motion resolutions, E and F), 1280x720 -> 1920x1080, 1001x563 -> 1501x845 (generic kernel),