Seed an SI run's source ledger, and the WATCH charter switch — POST **************** (X-Internal-Auth) takes {orgId, memberId, items:[{ref, excerpt}]}: 1-5 canonical refs with excerpts of at most 4,000 characters (else 400 items), labels them through LabelService and records each in the run's source ledger as a read of tool runtime:signal, its excerpt sealed (204); a run with no registered context of this SI is 404 RUN_CONTEXT_MISSING; an AUDIT org whose calls go une...