Docs: local Human names, Channel nicknames and stable mention labels #616

Parent

Related implementation parent: #126 (Human Inbox). Existing named Group Human receipt identity is owned by ADR-0078 / #347; this issue documents the newly confirmed editable-name behavior.

What to document

Record the confirmed local Human naming design in the bilingual Context, living architecture, and Release Ledger:

• One optional default Human display name in BotHarness plugin settings, falling back to Human.
• DM and Group Channel header menus provide My nickname and restore-default; Channel overrides inherit the default when cleared.
• Different roleplay names identify one Human and one personal Human Inbox, without creating accounts or roleplay background records.
• UI and Bot-facing current Channel context use the same resolved name.
• Typed stable-ID Human and PersonaBot mentions display current names even in historical messages, without rewriting Source Event content or retriggering notifications, Admissions, or wakes.
• Duplicate Human/Bot names are allowed with type disambiguation.
• External identity mapping and multi-Human login remain outside this local-name design.

Acceptance criteria

• English and Chinese product terms agree.
• Living architecture records the confirmed target separately from current runtime behavior.
• Bilingual Release Ledger and documentation checks pass.
• This PR contains only design documentation and does not include the pending Tracer: Trusted Bot @Human reaches personal Inbox mentions #549 runtime PR.

Further work

After this documentation PR merges, publish the complete specification and approved vertical implementation slices under #126. Runtime screenshots or video belong to those implementation PRs; this issue changes documentation only.