Phase 12: 統一TypeBox ABI実装開始 - ChatGPT5による極小コアABI基盤構築

- TypeBox ABI雛形: メソッドスロット管理システム追加
- Type Registry: Array/Map/StringBoxの基本メソッド定義
- Host API: C ABI逆呼び出しシステム実装
- Phase 12ドキュメント整理: 設計文書統合・アーカイブ化
- MIR Builder: クリーンアップと分離実装完了

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

Co-Authored-By: Claude <noreply@anthropic.com>

docs/archive/code/MIR_BUILDER_MODULARIZED.md

@@ -0,0 +1,14 @@
+# MIR Builder (modularized) — Archived
+
+Status: Archived. The optional feature `mir_modular_builder` and the module `src/mir/builder_modularized/*` have been removed.
+
+Reason:
+- The active MIR builder lives under `src/mir/builder/` and `src/mir/builder.rs`.
+- CI and default builds never enabled the modular builder feature; it diverged from the main path.
+
+Where to look now:
+- Current builder: `src/mir/builder/` and `src/mir/builder.rs`
+- MIR cleanup plan/spec: `docs/development/roadmap/phases/phase-11.8_mir_cleanup/{PLAN.md,TECHNICAL_SPEC.md}`
+
+Notes:
+- Any historical design details can be recovered from git history. This page exists as a breadcrumb for past references.