[samlaf]

Refs https://linear.app/seismic-systems/issue/SEI-1056/featattestation-7879-serves-deposit-data-for-the-bound-withdrawal

Was just trying to add the deposit paths in TEE world, and found the docs a bit hard to read. So just grouping the bullet lists into categories and adding a picture of all the data included in the deposit_data_root.

LLM Summary

Third-party deposit tooling, and the attestation service's deposit route, need to know what summit signs and what the deposit contract hashes. Neither was documented, and the bytes differ from Ethereum's.

• Add a Deposit data subsection with an SVG diagram (docs/diagrams/deposit-data.svg). It shows the message both keys sign, deposit_data_root, and how the signatures link the two.
• Note what is easy to get wrong when signing outside summit:
  • each key signs 0x00 ‖ message (commonware's namespace prefix), and BLS uses the given DST;
  • the message is not SSZ, while deposit_data_root is;
  • the amount is in gwei, as a little-endian u64.
• State in the Deposits rules what deposit() takes and that the contract does not check signatures; Summit does.
• Group the bullets in Deposits, Withdrawals, Validator Count Limits and Validator Balance under bold topic headings. Bullet text is unchanged apart from dropping an orphaned "Exception:" lead-in.
• staking-and-participating.md: stop calling the deposit flow exactly Ethereum's, and link to the new subsection.

[linear-code]

SEI-1056