Add FSR3 Generic API path and harden runtime diagnostics

- AmdFsr3Runtime now probes both the legacy ffxFsr3* API and the newer
  generic ffxCreateContext/ffxDispatch API; selects whichever the loaded
  runtime library exports (GenericApi takes priority fallback)
- Generic API path implements full upscale + frame-generation context
  creation, configure, dispatch, and destroy lifecycle
- dlopen error captured and surfaced in lastError_ on Linux so runtime
  initialization failures are actionable
- FSR3 runtime init failure log now includes path kind, error string,
  and loaded library path for easier debugging
- tools/generate_ffx_sdk_vk_permutations.sh added: auto-bootstraps
  missing VK permutation headers; DXC auto-downloaded on Linux/Windows
  MSYS2; macOS reads from PATH (CI installs via brew dxc)
- CMakeLists: add upscalers/include to probe include dirs, invoke
  permutation script before SDK build, scope FFX pragma/ODR warning
  suppressions to affected TUs, add runtime-copy dependency on wowee
- UI labels updated from "FSR2" → "FSR3" in settings, tuning panel,
  performance HUD, and combo boxes
- CI macOS job now installs dxc via Homebrew for permutation codegen

.github/workflows/build.yml

@@ -138,7 +138,7 @@ jobs:
 
       - name: Install dependencies
         run: |
-          brew install cmake pkg-config sdl2 glew glm openssl@3 zlib ffmpeg unicorn \
+          brew install cmake pkg-config sdl2 glew glm openssl@3 zlib ffmpeg unicorn dxc \
             stormlib vulkan-loader vulkan-headers shaderc dylibbundler || true
           # dylibbundler may not be in all brew mirrors; install separately to not block others
           brew install dylibbundler 2>/dev/null || true