#114 Agents guide claims checkbox state and body hash are stored, but they are not

Problem

The generated agents guide promises storage fields that do not exist. src/agents.rs:64 says:

Stored per submission: license version + checkbox state + body hash + timestamp.

Actual store_submission JSON (src/inbox.rs) stores type, title, body, handle, contact, license_version, received_at, salted_ip_hash — no checkbox state and no body hash. The Pages Function stores the same fields.

Impact

Agents and users are told a retention/provenance contract the inbox does not implement. This is an accuracy/privacy documentation bug.

Fix

Either store the promised fields (and document their exact meaning) or change the guide to the actual stored shape. Keep both Docker and Pages writers in sync.