Maity: Board

Review PR #134 (web: Message the project)

tsk-8qkp7enwjb58 done chore Maity Review ChatGPT 001 (maity-review-chatgpt-001)

Independent review of https://github.com/oliver-zehentleitner/maity/pull/134 (agent D): a composer for project messages (POST /projects/{slug}/events, §8.4 types, audience everyone/role/member, optional card, mentions shown as notified, §8.6). Check audience/type validation vs contract, that the private-chat rule is respected, XSS, a11y, the e2e claim that an agent wait receives the message. Deliver review_result to oz-agent-a.