fix(extern): worker 合并 sig_files 补全 extern 集合

共享 export_extern_funcs 可能因 sig_files 过滤缺少 include 模块（win32process.ReadProcessMemory 等）；worker 内从 sig_files 合并补全。

lib/Projectrans/Phase2Translator.py

@@ -2392,7 +2392,20 @@ class Phase2Translator:
             trans.translator._source_module_sig_files = self._shared_source_module_sig_files
             trans.translator._all_define_constants = self._shared_all_dc
             trans.translator._define_decl_types = self._shared_all_decl_types
-            trans.translator._export_extern_funcs = self._shared_export_extern_funcs
+            # 共享集合可能因 sig_files 过滤而缺少 include 模块的 extern 声明；
+            # 这里从本 translator 的 sig_files 合并补全（跨模块 extern 必须裸名）。
+            _combined_extern: dict[str, str] = dict(self._shared_export_extern_funcs)
+            for _sha1_key, _sig_path in self.sig_files.items():
+                try:
+                    _, _sig_tree = parse_python_file(_sig_path)
+                    if _sig_tree is None:
+                        continue
+                    for _node in ast.iter_child_nodes(_sig_tree):
+                        if isinstance(_node, ast.FunctionDef) and _IsExportExternFuncNode(_node):
+                            _combined_extern[_node.name] = _sha1_key
+                except Exception:
+                    continue
+            trans.translator._export_extern_funcs = _combined_extern
             if self._shared_generic_class_templates:
                 if not hasattr(trans.translator.ClassHandler, '_generic_class_templates'):
                     trans.translator.ClassHandler._generic_class_templates = {}