The rebase onto master picked up #585 (agent-loop message machine), which
removed the request-only session-prefix seam; the unified sourced-message
decision now owns the mechanism and the note's own banner declares the
seam removed. Archive the triplet and rewrite the skill-system note's
catalog mechanism against the shipped agent/step sourced injection,
keeping the archived note as the intentional historical citation.
Re-checked the other notes master added or amended (provider retry
policies, request-error retry action, observable state machine, OTel
telemetry, dependabot): their supersessions were already executed
upstream in the same PRs; no further active note qualifies.
Tianyi Cui