Fix VRAM leak on quality changes and RGBA16 motion vectors; more games

- Shim: reuse VRAM interop buffers across features instead of freeing them;
  ROCm 7.2.x's hipExternalMemoryGetMappedBuffer retains its view twice, so
  freed buffers never released their memory (~130 MB per quality change)
- Bridge: close the exported fd after hipImportExternalMemory
- Shim: accept R16G16B16A16_TYPELESS motion vectors and convert 4-channel
  motion vectors to RG16F on the GPU, keeping VRAM interop (Dying Light:
  The Beast rendered black)
- Harness: D4R_HARNESS_RECREATE=N quality-change cycles,
  D4R_HARNESS_MV_RGBA16=1 motion vector format
- Supported games: TLOU, Control, Cyberpunk 2077, Rift Apart, HZD Remastered,
  Subnautica 2, Alan Wake 2, Silent Hill 2, Dying Light: The Beast; general notes
- README: GPU support section (native kernels only for gfx1101); ignore videos/

.gitignore

@@ -23,6 +23,7 @@ __pycache__/
 /Archive.zip
 /vkd3d-proton.cache
 .vscode/
+videos/
 
 # Machine-specific notes, CI runner setup, local experiments, benchmark automation (kept locally, never published)
 /private/
@@ -32,4 +33,4 @@ __pycache__/
 /kernels/out/
 *.hsaco
 *.ptx
-/kernels/extracted/
+/kernels/extracted/