cb8de0f28a
- 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