Identity + memory bootstrap

CALL THIS FIRST in every session. The ids returned here feed every other
read tool. Skip the bootstrap and you will re-investigate things the team
already established.

USE WHEN: starting any session; deciding where to resume; seeing which
peer agents are active.
DO NOT USE: to search or rank content for a task (use get_context(task:)).

Returns flat identity keys (account_id, account_name, account_email,
user_id, user_name, user_email, role), plus agent (with previous_seen_at
so you know what changed since you were last here), account (memory_count +
last_changed_at), topics (the memory pages, newest first with a snippet
each; this is what the team currently knows, read it before asking),
memories_since_previous_seen (count + memory_ids of pages updated since
your previous connection; skip what was already there and focus on the
new), recently_active_agents (peers seen in last 15 min), agents_md_uri,
agents_md_version (re-fetch the manual when this changes).