feat: import defer 阶段标志纳入模块哈希键

crates/oxide_compiler/src/hash/statement.rs

@@ -98,6 +98,9 @@ pub(super) fn hash_statement(stmt: &Statement, h: &mut rustc_hash::FxHasher, inc
         }
         Statement::ImportDeclaration(imp) => {
             imp.source.value.hash(h);
+            // import 阶段标志（import defer / source-phase imports）：同源声明
+            // 语义不同，须区分缓存键，防 defer 与非 defer 碰撞复用错误字节码。
+            imp.phase.map(|p| p as u8).hash(h);
             if let Some(specifiers) = &imp.specifiers {
                 (specifiers.len() as u32).hash(h);
                 for spec in specifiers {

crates/oxide_compiler/tests/hash_collision_tests.rs

@@ -86,6 +86,27 @@ fn import_expression_distinguished() {
     assert_ne!(compiled("import('./a.js')"), compiled("import('./a.js', { with: { type: 'json' } })"));
 }
 
+#[test]
+fn import_defer_distinguished() {
+    // import defer 与普通 namespace import 语义不同（defer 不触发依赖求值）：
+    // 修复前 phase 不入 hash，两者哈希相同 → 缓存碰撞复用错误字节码。
+    assert_ne!(
+        compiled("import defer * as ns from './x.js'"),
+        compiled("import * as ns from './x.js'"),
+        "import defer vs plain namespace import must differ"
+    );
+    assert_ne!(
+        structural("import defer * as ns from './x.js'"),
+        structural("import * as ns from './x.js'"),
+        "defer flag must be part of the structural key too"
+    );
+    // 同源等价回归
+    assert_eq!(
+        compiled("import defer * as ns from './x.js'"),
+        compiled("import defer * as ns from './x.js'")
+    );
+}
+
 #[test]
 fn structural_hash_ignores_binding_names() {
     // 结构哈希忽略绑定名：仅参数/变量改名后哈希相等。