fix: preserve native guardian calldata addresses

[LucienSong]

Summary

• encode guardian recovery identities as full native 32-byte ABI words
• retain the existing public selectors and calldata layout expected by AccountManager
• assert full-width address words across set, submit, execute, and cancel recovery helpers

This aligns the SDK with ShellDAO/shell-chain#330.

Verification

• npm run typecheck
• npm test (143 passed, 1 testnet test skipped)
• git diff --check