add TanStack Query query + mutation output targets

[swalker326]

Summary

• add a new CommandOutputTarget enum and Builder::command_output_target(...) config so command generation can target either invoke functions (default) or TanStack Query helpers
• when CommandOutputTarget::TanstackQuery is selected, generate commands.* wrappers that return queryOptions({ queryKey, queryFn }) using @tanstack/react-query, with query keys including command name and argument object when present
• add first-class mutation generation via Builder::mutation_commands([...]); commands in this set generate mutationOptions({ mutationKey, mutationFn }) while non-listed commands continue generating queryOptions
• expose the new output target + mutation config in the public API and document them in crate docs/README
• add a new end-to-end example app at examples/react-query-app that uses generated query and mutation helpers from React

How to test (new example app)

• pnpm install
• cargo run --manifest-path examples/react-query-app/src-tauri/Cargo.toml (generates examples/react-query-app/src/bindings.ts)
• pnpm --dir examples/react-query-app tauri dev
• in the app:
  • verify query helpers by changing the name and seeing greeting/list queries update
  • verify mutation helpers by adding/deleting todos and seeing list invalidation refresh results

Notes

• inspired by issue Tanstack Query queryOptions API #147 and follows its proposed queryOptions shape as the starting point
• full workspace cargo test --all --all-features still has unrelated example/plugin formatter API failures in this repo; validation used here:
  • cargo check -p tauri-specta --all-features --lib
  • cargo check -p tauri-specta-example-react-query-app
  • pnpm --dir examples/react-query-app exec tsc --noEmit
  • pnpm --dir examples/react-query-app build