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

tests/mir_builder_unit.rs

@@ -0,0 +1,67 @@
+use nyash_rust::mir::MirBuilder;
+use nyash_rust::ast::{ASTNode, LiteralValue, BinaryOperator, Span};
+
+#[test]
+fn test_literal_building() {
+    let mut builder = MirBuilder::new();
+    let ast = ASTNode::Literal {
+        value: LiteralValue::Integer(42),
+        span: Span::unknown(),
+    };
+    let result = builder.build_module(ast);
+    assert!(result.is_ok());
+    let module = result.unwrap();
+    assert_eq!(module.function_names().len(), 1);
+    assert!(module.get_function("main").is_some());
+}
+
+#[test]
+fn test_binary_op_building() {
+    let mut builder = MirBuilder::new();
+    let ast = ASTNode::BinaryOp {
+        left: Box::new(ASTNode::Literal {
+            value: LiteralValue::Integer(10),
+            span: Span::unknown(),
+        }),
+        operator: BinaryOperator::Add,
+        right: Box::new(ASTNode::Literal {
+            value: LiteralValue::Integer(32),
+            span: Span::unknown(),
+        }),
+        span: Span::unknown(),
+    };
+    let result = builder.build_module(ast);
+    assert!(result.is_ok());
+    let module = result.unwrap();
+    let function = module.get_function("main").unwrap();
+    let stats = function.stats();
+    assert!(stats.instruction_count >= 3);
+}
+
+#[test]
+fn test_if_statement_building() {
+    let mut builder = MirBuilder::new();
+    let ast = ASTNode::If {
+        condition: Box::new(ASTNode::Literal {
+            value: LiteralValue::Bool(true),
+            span: Span::unknown(),
+        }),
+        then_body: vec![ASTNode::Literal {
+            value: LiteralValue::Integer(1),
+            span: Span::unknown(),
+        }],
+        else_body: Some(vec![ASTNode::Literal {
+            value: LiteralValue::Integer(2),
+            span: Span::unknown(),
+        }]),
+        span: Span::unknown(),
+    };
+    let result = builder.build_module(ast);
+    assert!(result.is_ok());
+    let module = result.unwrap();
+    let function = module.get_function("main").unwrap();
+    assert!(function.blocks.len() >= 3);
+    let stats = function.stats();
+    assert!(stats.phi_count >= 1);
+}
+