When the default/global state.db is corrupt at gateway startup,
SessionStore degrades (_db=None) and record_gateway_session_peer never
self-heals. Under multiplexed profile routes the AIAgent's lazy
_ensure_db_session was then the ONLY durable write for the session, and
it created the row identity-less (session_key/chat_id/chat_type/
thread_id/user_id/origin_json all NULL) — unrecoverable by
find_latest_gateway_session_for_peer, so Telegram chats forgot prior
turns.
Persist the routing identity the agent already carries into
create_session; plain CLI sessions keep the old identity-less shape.
Salvaged leg 1 of #88804; the transcript-recovery leg is covered by the
scope-aware session DB resolution already on main.
