Create or upsert a memory entry by name. Returns { ok: true, entries: <count after the write> };
invalid input returns 400 and an unknown session 404. Staff writes work even when the project's
contact-memory feature is disabled.
Bearer <token>.Trimmed and truncated to 80 characters; the entry is keyed by this value.
Optional. Omitting it clears the stored description on update (full replace). Truncated to 240 characters.
Required. Truncated to 4000 characters.
Ok
Only set on internal (non-admin) calls; never present in an admin API 200 response.