`core teaching supersede <old_chain_id> --subject ... --intent ... --connective ...
--object ... --review-date YYYY-MM-DD` is the second corpus mutation surface
(alongside accept_proposal). No replay gate — it's a deliberate operator action
that replaces a hand-authored or previously discovery-promoted chain.
- teaching/supersede.py — `supersede_chain()` orchestrator with pre-checks
(review_date format, intent whitelist, pack-consistency via re-audit,
no double-supersede, no self-supersede, no new-chain-id collision) and
byte-identical rollback on post-audit failure.
- teaching/proposals.py — extended `append_chain_to_corpus` with optional
`superseded_by` kwarg; remains the only function in the codebase that
writes to the active teaching corpus.
- core/cli.py — `core teaching supersede` subcommand wired to the live
`_CORPUS_PATH`; EPILOG updated with example.
- tests/test_supersede.py — 13 tests pin every gate, byte-identical
rollback on rejection, append-only at disk level, audit-and-runtime
parity after supersession, hand_authored provenance with
`supersede(<old_chain_id>)` tag.
Lane state: smoke 67 / cognition 121 / teaching 17 / supersede 13 / audit 23 /
proposals 16 / contemplation 16 / contemplation-wiring 6 / discovery 24 — green.
`core eval cognition`: intent 100% / surface 100% / term 91.7% / versor 100% — unchanged.
