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.

packaging/SOURCES.txt

@@ -42,6 +42,10 @@ Third-party software, unmodified or patched by d4r:
                          License: d4r/licenses/OptiScaler-LICENSE-GPL-3.0.txt
   OptiScaler.ini         OptiScaler 0.9.4's OptiScaler.ini with the values d4r needs set
                          (packaging/optiscaler.settings in the d4r repository)
+  amd_fidelityfx_dx12.dll, amd_fidelityfx_upscaler_dx12.dll
+                         AMD FidelityFX SDK 2.3 loader and FSR 4.1.1 upscaler (MIT), unmodified, as shipped in
+                         the OptiScaler 0.9.4 release. https://github.com/GPUOpen-LibrariesAndSDKs/FidelityFX-SDK
+                         License: d4r/licenses/FidelityFX-LICENSE.txt
 
 @clean Not included: NVIDIA's DLSS libraries (nvngx_dlss.dll, nvngx_dlssd.dll) and NGX runtime (_nvngx.dll). You supply them
 @clean and are responsible for complying with NVIDIA's license terms.