docs(manifest): replace stale "67/67 Qed" claim with honest proof-debt pointer

The CORE INVARIANTS section in 0-AI-MANIFEST.a2ml claimed "All proofs
MUST remain closed (67/67 Qed)" — false as of mid-2026:

- formal/Semantics.v `preservation` is Admitted (provably FALSE per
  Counterexample.v's 3 Qed lemmas).
- formal/Semantics_L1.v carries 4+ admits + 1 Admitted Lemma
  region_liveness_at_split_l1_gen (post-#181) + 1 Admitted
  preservation_l1.

The trusted-base reduction policy (standards#203) is the canonical
enforcement mechanism — every escape hatch is enumerated by
file:line in docs/proof-debt.adoc. Replace the 67/67 number with a
pointer to that mechanism, and strengthen the rule: ANY new escape
hatch must be enumerated in docs/proof-debt.adoc before the
trusted-base CI check will pass.

Refs PR #176 (L2 hybrid), PR #181 (Axiom→Lemma), PR #164 (proof-debt
seed), standards#203.

Author: hyperpolymath

0-AI-MANIFEST.a2ml

@@ -23,7 +23,7 @@ These 6 A2ML files MUST exist in `.machine_readable/6a2/` directory ONLY:
 
 ## CORE INVARIANTS
 
-1. **Formal Proof Integrity** - No `Admitted` in Coq or `believe_me`/`assert_total` in Idris2. All proofs MUST remain closed (67/67 Qed).
+1. **Formal Proof Integrity** — Coq proofs are layered per the four-layer redesign (`formal/PRESERVATION-DESIGN.md`). The legacy `preservation` in `Semantics.v` is provably FALSE per `Counterexample.v` (3 Qed lemmas) and remains `Admitted`. The L1 preservation chain (`Semantics_L1.v`) is in flight; explicit `Admitted` / `admit.` / `Axiom` sites are enumerated by `file:line` in `docs/proof-debt.adoc` per the standards#203 trusted-base reduction policy. Idris2 source has no `believe_me` / `assert_total` / `sorry`. ANY new escape hatch must be enumerated in `docs/proof-debt.adoc` before the trusted-base CI check will pass.
 2. **Dyadic Separation** - The boundary between affine and linear types must be strictly enforced.
 3. **SPDX Headers** - All source files MUST carry `SPDX-License-Identifier: PMPL-1.0-or-later`.
 4. **Author Attribution** - Always "Jonathan D.A. Jewell <j.d.a.jewell@open.ac.uk>".