release: prepare 0.1.5 with RDNA2 kernels and in-game DLSS/FSR switching

- Add native preset K kernels for gfx1030–gfx1036 using software matrix
  products, with fast and accuracy builds and RDNA2 motion kernels.
- Follow OptiScaler's DLSS and RR preset overrides, sanitize unsupported
  values and select the preset matching the feature's quality mode.
- Enable FSR 4 under NVIDIA GPU spoofing by exposing real AMD PCI IDs
  to OptiScaler and FidelityFX modules; bundle AMD's loader and upscaler.
- Keep K on native kernels in engine auto mode unless HIP is selected,
  and fall back to CUDA for M/L when shader_float8 is unavailable.
- Add native-engine K GPU timings, preset recreation harness controls
  and regression coverage; fix the input-wait test's glibc name clash.
- Update configuration, installer guidance and release documentation,
  simplify the README and move gameplay videos to docs/videos.md.

RDNA2 kernels remain untested on RDNA2 hardware; software matrix
arithmetic was validated against WMMA on RDNA3.

scripts/d4r_config.py

@@ -87,6 +87,11 @@ def main(argv):
         else:
             fail(f"[DLSS] Model {model!r}: use one of {', '.join(list(PRESETS) + list(MODEL_ALIASES))} or a preset number")
 
+    if flag("OptiScaler", "FollowPresets") is False:
+        env["D4R_FOLLOW_OPTISCALER"] = "0"
+    if flag("OptiScaler", "Fsr4") is False:
+        env["D4R_FSR4_IDENTITY"] = "0"
+
     rr_enabled = flag("RayReconstruction", "Enable")
     if rr_enabled is not None:
         env["D4R_RR_ENABLE"] = "1" if rr_enabled else "0"