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

src/rendering/performance_hud.cpp

@@ -201,7 +201,7 @@ void PerformanceHUD::render(const Renderer* renderer, const Camera* camera) {
             }
         }
         if (renderer->isFSR2Enabled()) {
-            ImGui::TextColored(ImVec4(0.4f, 0.9f, 1.0f, 1.0f), "FSR 2.2: ON");
+            ImGui::TextColored(ImVec4(0.4f, 0.9f, 1.0f, 1.0f), "FSR 3 Upscale: ON");
             ImGui::Text("  JitterSign=%.2f", renderer->getFSR2JitterSign());
             const bool fgEnabled = renderer->isAmdFsr3FramegenEnabled();
             const bool fgReady = renderer->isAmdFsr3FramegenRuntimeReady();