Import hashi contracts and RoflAdapter via submodule instead of copying code

[rube-de]

Currently, both the RoflAdapter and hashi contracts are manually copied into this project. This approach can lead to code duplication and make it difficult to keep these dependencies up to date.

Proposal:

• Remove the manually-copied RoflAdapter and hashi contracts from the codebase.
• Import both as Git submodules instead.
• Update all references in the project to use the submodule paths.

Benefits:

• Single source of truth for dependencies.
• Reduced maintenance effort when upgrading hashi contracts or RoflAdapter.
• Minimize risk of using outdated or incorrect code copies.

Acceptance Criteria:

• RoflAdapter and hashi contracts are included via submodules.
• All references updated in the build system and import paths.
• Remove legacy copied code in the repository.
• Instructions for updating submodules documented in README or relevant docs.