Enough1122 review points on #94417:
1. Precedence hazard fixed: the busy-guard assertion now locates the
rebind helper body precisely and asserts the guard INSIDE it, instead
of a 2000-char window with an (m and X) or Y precedence trap.
2. stored_session_id guarantee: documented + pinned — the gateway always
stamps it ('stored_session_id': session_key or "" in server.py), and
the rebind's typeof check refuses non-string/empty values, so an
unnamed rebuilt runtime is never adopted as lineage proof.
3. New third assertion pins that refusal contract.
Structural smoke tests remain structural by design; the behavior
contract for the rebind is exercised end-to-end by the model-switch
manual repro path — a vitest harness driving handleSessionInfoEvent is
the follow-up candidate noted in the reply.
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