Phase 21.3 WIP: Hako Source Checker improvements

## 🎯 Checker/Analyzer拡張

### ✅ 実装追加
- テストフレームワーク追加（tools/hako_check/tests/）
- ルール改善（HC003グローバルassign、HC040静的箱トップレベルassign）
- テストランナー（run_tests.sh）

### 🔧 Rust側修正
- AST utilities拡張（src/ast/utils.rs）
- MIR lowerers新設（src/mir/lowerers/）
- Parser制御フロー改善（src/parser/statements/control_flow.rs）
- Tokenizer識別子処理改善（src/tokenizer/lex_ident.rs）

### 📁 主要変更
- tools/hako_check/cli.hako - CLI改善
- tools/hako_check/hako_source_checker.hako - Checker core更新
- tools/hako_check/tests/ - NEW (テストケース追加)
- tools/hako_check/run_tests.sh - NEW (テストランナー)
- src/mir/lowerers/ - NEW (MIR lowering utilities)

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

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

src/ast/utils.rs

@@ -12,6 +12,8 @@ impl ASTNode {
             ASTNode::Print { .. } => "Print",
             ASTNode::If { .. } => "If",
             ASTNode::Loop { .. } => "Loop",
+            ASTNode::While { .. } => "While",
+            ASTNode::ForRange { .. } => "ForRange",
             ASTNode::Return { .. } => "Return",
             ASTNode::Break { .. } => "Break",
             ASTNode::Continue { .. } => "Continue",
@@ -62,6 +64,8 @@ impl ASTNode {
             ASTNode::FunctionDeclaration { .. } => ASTNodeType::Structure,
             ASTNode::If { .. } => ASTNodeType::Structure,
             ASTNode::Loop { .. } => ASTNodeType::Structure,
+            ASTNode::While { .. } => ASTNodeType::Structure,
+            ASTNode::ForRange { .. } => ASTNodeType::Structure,
             ASTNode::TryCatch { .. } => ASTNodeType::Structure,
 
             // Expression nodes - 値を生成する表現
@@ -140,6 +144,20 @@ impl ASTNode {
             } => {
                 format!("Loop({} statements)", body.len())
             }
+            ASTNode::While {
+                condition: _, body, ..
+            } => {
+                format!("While({} statements)", body.len())
+            }
+            ASTNode::ForRange {
+                var_name,
+                start: _,
+                end: _,
+                body,
+                ..
+            } => {
+                format!("ForRange(var={}, {} statements)", var_name, body.len())
+            }
             ASTNode::Return { value, .. } => {
                 if value.is_some() {
                     "Return(with value)".to_string()
@@ -329,6 +347,8 @@ impl ASTNode {
             ASTNode::Print { span, .. } => *span,
             ASTNode::If { span, .. } => *span,
             ASTNode::Loop { span, .. } => *span,
+            ASTNode::While { span, .. } => *span,
+            ASTNode::ForRange { span, .. } => *span,
             ASTNode::Return { span, .. } => *span,
             ASTNode::Break { span, .. } => *span,
             ASTNode::Continue { span, .. } => *span,