chore: Phase 25.1 完了 - LoopForm v2/Stage1 CLI/環境変数削減 + Phase 26-D からの変更

Phase 25.1 完了成果:
- ✅ LoopForm v2 テスト・ドキュメント・コメント完備
  - 4ケース（A/B/C/D）完全テストカバレッジ
  - 最小再現ケース作成（SSAバグ調査用）
  - SSOT文書作成（loopform_ssot.md）
  - 全ソースに [LoopForm] コメントタグ追加

- ✅ Stage-1 CLI デバッグ環境構築
  - stage1_cli.hako 実装
  - stage1_bridge.rs ブリッジ実装
  - デバッグツール作成（stage1_debug.sh/stage1_minimal.sh）
  - アーキテクチャ改善提案文書

- ✅ 環境変数削減計画策定
  - 25変数の完全調査・分類
  - 6段階削減ロードマップ（25→5、80%削減）
  - 即時削除可能変数特定（NYASH_CONFIG/NYASH_DEBUG）

Phase 26-D からの累積変更:
- PHI実装改善（ExitPhiBuilder/HeaderPhiBuilder等）
- MIRビルダーリファクタリング
- 型伝播・最適化パス改善
- その他約300ファイルの累積変更

🎯 技術的成果:
- SSAバグ根本原因特定（条件分岐内loop変数変更）
- Region+next_iパターン適用完了（UsingCollectorBox等）
- LoopFormパターン文書化・テスト化完了
- セルフホスティング基盤強化

Co-Authored-By: Claude <noreply@anthropic.com>
Co-Authored-By: ChatGPT <noreply@openai.com>
Co-Authored-By: Task Assistant <task@anthropic.com>

src/mir/builder/emission/branch.rs

@@ -1,15 +1,24 @@
 //! BranchEmissionBox — 分岐/ジャンプ命令発行の薄いヘルパ（仕様不変）
 
-use crate::mir::{BasicBlockId, MirInstruction};
 use crate::mir::builder::MirBuilder;
+use crate::mir::{BasicBlockId, MirInstruction};
 
 #[inline]
-pub fn emit_conditional(b: &mut MirBuilder, cond: crate::mir::ValueId, then_bb: BasicBlockId, else_bb: BasicBlockId) -> Result<(), String> {
+pub fn emit_conditional(
+    b: &mut MirBuilder,
+    cond: crate::mir::ValueId,
+    then_bb: BasicBlockId,
+    else_bb: BasicBlockId,
+) -> Result<(), String> {
     if let (Some(func), Some(cur_bb)) = (b.current_function.as_mut(), b.current_block) {
         crate::mir::ssot::cf_common::set_branch(func, cur_bb, cond, then_bb, else_bb);
         Ok(())
     } else {
-        b.emit_instruction(MirInstruction::Branch { condition: cond, then_bb, else_bb })
+        b.emit_instruction(MirInstruction::Branch {
+            condition: cond,
+            then_bb,
+            else_bb,
+        })
     }
 }
 

src/mir/builder/emission/compare.rs

@@ -1,10 +1,16 @@
 //! CompareEmissionBox — 比較命令発行の薄いヘルパ（仕様不変）
 
-use crate::mir::{CompareOp, MirInstruction, MirType, ValueId};
 use crate::mir::builder::MirBuilder;
+use crate::mir::{CompareOp, MirInstruction, MirType, ValueId};
 
 #[inline]
-pub fn emit_to(b: &mut MirBuilder, dst: ValueId, op: CompareOp, lhs: ValueId, rhs: ValueId) -> Result<(), String> {
+pub fn emit_to(
+    b: &mut MirBuilder,
+    dst: ValueId,
+    op: CompareOp,
+    lhs: ValueId,
+    rhs: ValueId,
+) -> Result<(), String> {
     if let (Some(func), Some(cur_bb)) = (b.current_function.as_mut(), b.current_block) {
         crate::mir::ssot::cf_common::emit_compare_func(func, cur_bb, dst, op, lhs, rhs);
     } else {
@@ -18,12 +24,22 @@ pub fn emit_to(b: &mut MirBuilder, dst: ValueId, op: CompareOp, lhs: ValueId, rh
 // Convenience wrappers (明示関数名が読みやすい箇所用)
 #[inline]
 #[allow(dead_code)]
-pub fn emit_eq_to(b: &mut MirBuilder, dst: ValueId, lhs: ValueId, rhs: ValueId) -> Result<(), String> {
+pub fn emit_eq_to(
+    b: &mut MirBuilder,
+    dst: ValueId,
+    lhs: ValueId,
+    rhs: ValueId,
+) -> Result<(), String> {
     emit_to(b, dst, CompareOp::Eq, lhs, rhs)
 }
 
 #[inline]
 #[allow(dead_code)]
-pub fn emit_ne_to(b: &mut MirBuilder, dst: ValueId, lhs: ValueId, rhs: ValueId) -> Result<(), String> {
+pub fn emit_ne_to(
+    b: &mut MirBuilder,
+    dst: ValueId,
+    lhs: ValueId,
+    rhs: ValueId,
+) -> Result<(), String> {
     emit_to(b, dst, CompareOp::Ne, lhs, rhs)
 }

src/mir/builder/emission/constant.rs

@@ -3,47 +3,65 @@
 //! ✅ Phase 25.1b Fix: All constant emission now uses function-local ID generator
 //! when inside a function context to ensure proper SSA verification.
 
-use crate::mir::{ConstValue, MirInstruction, ValueId};
 use crate::mir::builder::MirBuilder;
+use crate::mir::{ConstValue, MirInstruction, ValueId};
 
 #[inline]
 pub fn emit_integer(b: &mut MirBuilder, val: i64) -> ValueId {
     let dst = b.next_value_id();
-    let _ = b.emit_instruction(MirInstruction::Const { dst, value: ConstValue::Integer(val) });
+    let _ = b.emit_instruction(MirInstruction::Const {
+        dst,
+        value: ConstValue::Integer(val),
+    });
     dst
 }
 
 #[inline]
 pub fn emit_bool(b: &mut MirBuilder, val: bool) -> ValueId {
     let dst = b.next_value_id();
-    let _ = b.emit_instruction(MirInstruction::Const { dst, value: ConstValue::Bool(val) });
+    let _ = b.emit_instruction(MirInstruction::Const {
+        dst,
+        value: ConstValue::Bool(val),
+    });
     dst
 }
 
 #[inline]
 pub fn emit_float(b: &mut MirBuilder, val: f64) -> ValueId {
     let dst = b.next_value_id();
-    let _ = b.emit_instruction(MirInstruction::Const { dst, value: ConstValue::Float(val) });
+    let _ = b.emit_instruction(MirInstruction::Const {
+        dst,
+        value: ConstValue::Float(val),
+    });
     dst
 }
 
 #[inline]
 pub fn emit_string<S: Into<String>>(b: &mut MirBuilder, s: S) -> ValueId {
     let dst = b.next_value_id();
-    let _ = b.emit_instruction(MirInstruction::Const { dst, value: ConstValue::String(s.into()) });
+    let _ = b.emit_instruction(MirInstruction::Const {
+        dst,
+        value: ConstValue::String(s.into()),
+    });
     dst
 }
 
 #[inline]
 pub fn emit_null(b: &mut MirBuilder) -> ValueId {
     let dst = b.next_value_id();
-    let _ = b.emit_instruction(MirInstruction::Const { dst, value: ConstValue::Null });
+    let _ = b.emit_instruction(MirInstruction::Const {
+        dst,
+        value: ConstValue::Null,
+    });
     dst
 }
 
 #[inline]
 pub fn emit_void(b: &mut MirBuilder) -> ValueId {
     let dst = b.next_value_id();
-    let _ = b.emit_instruction(MirInstruction::Const { dst, value: ConstValue::Void });
+    let _ = b.emit_instruction(MirInstruction::Const {
+        dst,
+        value: ConstValue::Void,
+    });
     dst
 }

src/mir/builder/emission/mod.rs

@@ -3,6 +3,6 @@
 //! - compare.rs: Compare命令の薄い発行
 //! - branch.rs: Branch/Jump 発行の薄い関数
 
-pub mod constant;
-pub mod compare;
 pub mod branch;
+pub mod compare;
+pub mod constant;