Replace install -D with mkdir -p + install for macOS portability,
add vitest with jsdom and testing-library, configure eslint for
react-hooks v7 warnings, and add tokio test deps for Rust.
Add Rust backend: AppState with connection pool management,
TuskError handling, ConnectionConfig model, and all commands
for connections, schema browsing, query execution, data CRUD,
and CSV/JSON export via sqlx.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>