init template: support package manager selection and update templates to @xahau

[tequdev]

High Level Overview of Change

The hooks-cli init project templates were still on the old @transia/* packages. This updates them to @xahau/hooks-toolkit (2.1.0) / xahau, and adds the ability to choose a package manager for the generated project.

Context of Change

• Updated init templates to the @xahau packages
  • Replaced @transia/xrpl -> xahau and @transia/hooks-toolkit -> @xahau/hooks-toolkit, and followed the API changes (setHooksV3 -> setHooks, seed -> wallet, SetHookFlags -> HookFlags, etc.)
  • Pinned @xahau/hooks-toolkit to ^2.1.0
• Added a --package-manager option to init
  • Choose from npm / yarn / pnpm (defaults to npm)
  • Rewrites npm calls in the generated package.json's scripts to the selected package manager
  • Exits with an error on an invalid value
• Expanded CI and tests
  • Bumped node-version from 16.x, 20.x to 20.x, 22.x, 24.x, 26.x, and added pnpm setup
  • Added an integration test (test/integration/init-build.test.ts) that actually runs install / build for each package manager after init
  • Added unit tests for the deploy script rewrite when --package-manager is specified, and for rejecting invalid values
• Updated README
  • Documented init usage and the new --package-manager option

Type of Change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Refactor (non-breaking change that only restructures code)
• Tests (You added tests for code that already exists, or your new feature included in this PR)
• Documentation Updates
• Release

Before / After

Test Plan