Core-13 pure: add CI workflows, VM e2e tests, LLVM parity bridge (minimal); do not touch private docs

CHANGELOG.md

@@ -2,11 +2,15 @@
 
 This changelog tracks high‑level milestones while Core MIR and Phase 12 evolve. For detailed per‑file history, see git log and docs under `docs/development/roadmap/`.
 
+## 2025‑09‑06
+- Core‑13 flip complete: code/tests enforce Core‑13 minimal kernel. Normalizations (Array/Ref→BoxCall, TypeCheck/Cast/Barrier/WeakRef unification) are ON by default via env (NYASH_MIR_CORE13=1). New tests validate normalization.
+- Docs synced: step‑50 marked done; DEV quickstart points to Core‑13 reference.
+
 ## 2025‑09‑04
 - Phase 12.7‑A complete: peek, continue, `?` operator, lambda, field type annotations. Language reference updated.
 - Phase 12.7‑B (basic) complete: parser‑level desugaring for `|>`, `?.`, `??`, `+=/-=/*=/=`, `..` behind `NYASH_SYNTAX_SUGAR_LEVEL`.
 - Docs: language reference and Phase 12.7 README updated to reflect basic completion; extensions tracked under gated plan.
-- MIR Core migration: enforcing Core‑15 in code/tests during transition; Core‑13 target defined in docs; final flip planning in progress.
+- MIR Core migration: previously enforcing Core‑15 during transition; superseded by 2025‑09‑06 Core‑13 flip.
 
 ## 2025‑09‑03
 - Nyash ABI TypeBox integration stabilized across core boxes; differential tests added; loader defaults adjusted (builtin + plugins).
@@ -14,5 +18,5 @@ This changelog tracks high‑level milestones while Core MIR and Phase 12 evolve
 ---
 
 Notes
-- “Core‑15 vs Core‑13” migration: Implementation currently enforces 15 for stability; docs include Core‑13 target reference. Final flip (docs/refs/entrypoints) is tracked under `docs/development/roadmap/mir/core-13/step-50/`.
+- Core‑13 is canonical minimal kernel. Historical Core‑15 notes remain under `docs/development/roadmap/` for reference.
 - Phase 12.7‑B desugaring is gated by `NYASH_SYNTAX_SUGAR_LEVEL`; tokenizer additions are non‑breaking.