refactor: 动态编译改经 CompilerService 注入，oxide_vm 去编译器依赖

crates/oxide_vm/tests/switch_default_tests.rs

@@ -7,6 +7,7 @@
 use std::sync::Arc;
 
 use oxide_compiler::compiler::Compiler;
+use oxide_compiler::DefaultCompilerService;
 use oxide_types::value::JsValue;
 use oxide_vm::vm::Vm;
 
@@ -15,6 +16,7 @@ fn eval(source: &str) -> Result<JsValue, String> {
     let program = oxide_parser::parse(&allocator, source).map_err(|e| format!("Parse: {:?}", e))?;
     let module = Compiler::new().compile(&program).map_err(|e| format!("Compile: {}", e))?;
     let mut vm = Vm::new();
+    vm.set_compiler_service(Arc::new(DefaultCompilerService));
     vm.run(&Arc::new(module))
 }
 
@@ -24,6 +26,7 @@ fn eval_str(source: &str) -> String {
     let program = oxide_parser::parse(&allocator, source).expect("parse");
     let module = Compiler::new().compile(&program).expect("compile");
     let mut vm = Vm::new();
+    vm.set_compiler_service(Arc::new(DefaultCompilerService));
     let value = vm.run(&Arc::new(module)).expect("run");
     assert!(value.is_string(), "expected string, got {value:?}");
     // SAFETY: is_string 已确认值为字符串指针，内容在 VM 析构前拷贝为自有 String。