audit: document stack overview refinement

AUDITS.md

@@ -44,7 +44,7 @@ Status legend: ✅ completed, ⬜ pending.
 16. ✅ `tier1/tgk-prov-1.md`
 17. ✅ `tier1/opreg-pel1-kernel.md`
 18. ✅ `tier1/opreg-pel1-kernel-params-1.md`
-19. ⬜ `tier1/amduat20-stack-overview.md`
+19. ✅ `tier1/amduat20-stack-overview.md`
 
 ## 2025-12-22 — ASL/1-CORE (`tier1/asl-1-core.md`)
 - Scope: ASL/1-CORE conformance for value semantics, encoding profiles, and
@@ -264,3 +264,15 @@ Status legend: ✅ completed, ⬜ pending.
   u32 bound; added a regression test that feeds an oversized `params_bytes`
   length and expects `INVALID_PROGRAM`.
 - Tests: user reported “100% tests passed, 0 tests failed out of 14”.
+
+## 2025-12-22 — SUBSTRATE/STACK-OVERVIEW (`tier1/amduat20-stack-overview.md`)
+- Scope: orientation doc maintenance; align overview to this repo’s implemented
+  kernel + near-core stack and avoid implying unsupported/deferred layers.
+- Findings: overview included deferred up-stack profile details, PH06-specific
+  evidence hooks, and a stray embedded “commit message” appendix, making it
+  look more normative and broader than the repo’s current scope.
+- Resolution: trimmed to implemented stack; replaced references to deferred
+  profiles with “future profiles” language; removed PH06 evidence hooks and the
+  embedded commit-message appendix; tightened wording throughout; bumped the
+  document version/date.
+- Tests: N/A (documentation-only change).