docs(licence-policy): restore A6+A7 dropped by #143/#144 merge race (#146)

A6/A7 were lost when #144 (A8) squash-merged over #143 (A6/A7) — both
edited the same anchor. Guard code (rsr#66) unaffected; restores the
policy-doc record. Refs LICENCE-DEBT-LEDGER-2026-05-18.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-authored-by: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: hyperpolymath

LICENCE-POLICY.adoc

@@ -156,6 +156,46 @@ sentinel with `REPLACE-WITH-*`); `spdx-policy-guard.yml` hard-fails it
 as a real SPDX value (and surfaces A3 variants as non-failing
 warnings). Evidence: `LICENCE-DEBT-LEDGER-2026-05-18`.
 
+=== A6 — Named hard-exclusions (enforced, not docs-only)
+
+Two repos are permanently excluded from the SPDX policy guard
+(owner-ruled 2026-05-19). This is *enforced* in
+`rsr-template-repo/.github/workflows/spdx-policy-guard.yml` (a
+repo-name early-exit), not merely documented here:
+
+* **`palimpsest-license`** — it *defines* the PMPL / PLMP / PMLP
+  identifiers; its spec and legal text legitimately contain many SPDX
+  strings, so scanning it produces guaranteed false positives and
+  could corrupt the licence specification.
+* **`repos-monorepo`** — a 297-submodule aggregate superproject that
+  only mirrors the standalone source repos (and harbours `007`, see
+  A1). Every hit duplicates a source repo; licence fixes belong in the
+  source repos only, never here.
+
+=== A7 — Known multi-SPDX false positives (ignore-list)
+
+A small, named set of files legitimately carry more than one SPDX
+*string* without being a licence contradiction — the extra strings are
+documentation-fenced examples, UI string-literals, or codegen-emitted
+headers. These are owner-ruled false positives (2026-05-19, ledger §A +
+§C C1–C3) and the guard reports them as a non-failing `::notice`:
+
+[cols="2,2,3"]
+|===
+| File (repo-relative) | Repo | Why it is not a contradiction
+
+| `PALIMPSEST.adoc`  | standards     | SPDX ids appear inside doc example blocks
+| `README.adoc`      | llm-grace     | PMPL references are explanatory prose, not a header
+| `…/App.res`        | ephapax       | the second id (EUPL-1.2) is a UI string-literal
+| `…/state-utils.scm`| wp-resurrect  | the second id (AGPL) is a codegen-emitted header
+| `CONTRIBUTING.md`  | flatracoon    | extra SPDX ids are fenced documentation examples
+|===
+
+These remain *visible* (`::notice`, not silenced) so the list can be
+audited and tightened. Genuine contradiction §C-C4 (zotero-voyant-export
+`ECHIDNA_ARCHITECTURE_UPDATE_3LANG.md`) is **not** on this list — it is
+a real defect tracked for an owner-directed single-file fix.
+
 === A8 — Explicit owner-sanctioned scoped carve-outs (2026-05-19)
 
 A2 forbids *automated/bulk* SPDX change as a standing default. The