Merge upstream main (v0.2.31) into openxr-work

Brings in 25 upstream commits: Dolphin-compatible input expressions and
GCPadNew.ini import, NAND setting.txt console identity, empty-MKW-save
handling, rumble toggle, LLVM 22, and CI caching.

The only conflict was runtime/CMakeLists.txt, where both sides appended
test targets after mkw_platform_paths_tests. Both blocks are kept: the VR
first-person test alongside upstream's NAND save/settings, SC serial, and
input expression tests.

runtime_config.h and settings_overlay.cpp auto-merged; the VR settings
menu, recenter hotkey, and stereo/first-person init calls are intact
alongside upstream's InputBindings wiring.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

.gitignore

@@ -26,6 +26,8 @@ Code.pul
 /build/
 /build-*/
 /native-build/
+/native-build-macos/
+/local-products/
 /dist/
 /out/
 [Bb]in/
@@ -71,3 +73,5 @@ project.lock.json
 *.log
 output.txt
 
+# Operating System
+.DS_Store