pyvm: split op handlers into ops_core/ops_box/ops_ctrl; add ops_flow + intrinsic; delegate vm.py without behavior change

net-plugin: modularize constants (consts.rs) and sockets (sockets.rs); remove legacy commented socket code; fix unused imports
mir: move instruction unit tests to tests/mir_instruction_unit.rs (file lean-up); no semantic changes
runner/pyvm: ensure using pre-strip; misc docs updates

Build: cargo build ok; legacy cfg warnings remain as before

src/ast/utils.rs

@@ -47,6 +47,8 @@ impl ASTNode {
             ASTNode::Lambda { .. } => "Lambda",
             ASTNode::ArrayLiteral { .. } => "ArrayLiteral",
             ASTNode::MapLiteral { .. } => "MapLiteral",
+            // Optional diagnostic-only wrapper
+            ASTNode::ScopeBox { .. } => "ScopeBox",
         }
     }
 
@@ -82,6 +84,9 @@ impl ASTNode {
             ASTNode::ArrayLiteral { .. } => ASTNodeType::Expression,
             ASTNode::MapLiteral { .. } => ASTNodeType::Expression,
 
+            // Diagnostic-only wrapper treated as structure
+            ASTNode::ScopeBox { .. } => ASTNodeType::Structure,
+
             // Statement nodes - 実行可能なアクション
             ASTNode::Program { .. } => ASTNodeType::Statement, // プログラム全体
             ASTNode::Assignment { .. } => ASTNodeType::Statement,
@@ -309,6 +314,7 @@ impl ASTNode {
             ASTNode::MapLiteral { entries, .. } => {
                 format!("MapLiteral({} entries)", entries.len())
             }
+            ASTNode::ScopeBox { .. } => "ScopeBox".to_string(),
         }
     }
 
@@ -355,6 +361,7 @@ impl ASTNode {
             ASTNode::Lambda { span, .. } => *span,
             ASTNode::ArrayLiteral { span, .. } => *span,
             ASTNode::MapLiteral { span, .. } => *span,
+            ASTNode::ScopeBox { span, .. } => *span,
         }
     }
 }