Support dart2wasm / Flutter --wasm via wasm_ffi 2.4.0

[vm75]

Summary

Updates universal_ffi to consume wasm_ffi: ^2.4.0 to inherit full WebAssembly compatibility for applications compiled with dart2wasm and Flutter Web --wasm.

References:

• vm75/wasm_ffi issue #13
• vm75/wasm_ffi PR #12
• wasm_ffi 2.4.0

Exact Dependency Change

• Upgraded wasm_ffi constraint in pubspec.yaml from ^2.3.0 to ^2.4.0.
• Preserved minimum Dart SDK constraint (^3.10.8).

Production Code Changes

• No production code changes were required in lib/. The clean facade architecture of universal_ffi seamlessly delegates WebAssembly loading, exports discovery, and 64-bit BigInt marshalling to wasm_ffi 2.4.0 without requiring duplicate wrappers.

Exact Tooling Versions Tested

• Dart SDK: 3.10.8 (stable) (Tue Jan 27 00:02:04 2026 -0800) on 'linux_x64'
• Flutter SDK: 3.38.9 (channel stable)
• Chromium: 151.0.7922.75 Arch Linux
• Node.js: v25.8.1

Validation Commands Run

dart pub get
dart format --output=none --set-exit-if-changed .
dart analyze
dart test
dart test -p chrome test/web_integration_test.dart
dart pub publish --dry-run
cd example_ffi_plugin/example
flutter analyze
flutter build web
flutter build web --wasm
node ../../tool/browser_smoke.mjs build/web

Runtime Test Results

• Flutter Web (dart2js): PASS. Both emscripten/native_example.js and standalone/native_example.wasm were loaded, looking up functions and successfully executing string conversions, size checks, and C++ static initialization.
• Flutter Web (--wasm / dart2wasm): PASS. Verified end-to-end function invocation and C++ static init in Chromium headless browser for both standalone Wasm and Emscripten modules.
• Standalone Wasm: PASS. Verified standalone .wasm function lookup, 32-bit addition, 64-bit BigInt addition, and pointer memory read/writes via FfiHelper.safeUsing.
• Emscripten Regression: PASS. Verified Emscripten JavaScript glue module resolution and invocation without regressions.
• Native VM: PASS. Verified Linux dynamic library loading and function calls via FfiHelper.

CI Changes

• Fixed root-package CHANGELOG inspection path in .github/workflows/publish.yml so validation is not skipped.
• Added .github/workflows/ci.yml for automated PR and push validation across formatting, analysis, VM tests, package dry-run, and Flutter Web (dart2js & --wasm) builds.

Version and CHANGELOG

• Bumped package version to 1.5.1 in pubspec.yaml.
• Updated CHANGELOG.md with 1.5.1 release notes.
• Updated README.md and AGENTS.md.

Package Publication

• No package was published as part of this PR.