- BUILD.md: complete build instructions for macOS desktop (Xcode 26.5,
Flutter 3.44, Dart 3.12, VCPKG, all patches explained)
- res/post-build-mac.sh: re-sign + install to /Applications + create dmg,
run after every 'flutter build macos --release'
Key issues documented in BUILD.md:
* Re-signing is mandatory (codesign --force --deep -s -)
* Use hdiutil for dmg, not create-dmg (macos-alias is x86_64 broken)
* libclang must be arm64 (use Xcode CLT, not homebrew llvm)
* EXCLUDED_ARCHS=x86_64 for arm64-only Rust dylib
xuwenwei