fix atomic writes for config manager

Author: yaugenst-flex

tidy3d/config/manager.py

@@ -301,27 +301,35 @@ def _reload(self) -> None:
 
     def _build_models(self) -> None:
         sections = get_sections()
-        self._section_models.clear()
-        self._plugin_models.clear()
+        new_sections: dict[str, BaseModel] = {}
+        new_plugins: dict[str, BaseModel] = {}
 
+        errors: list[tuple[str, Exception]] = []
         for name, schema in sections.items():
             if name.startswith("plugins."):
                 plugin_name = name.split(".", 1)[1]
                 plugin_data = _deep_get(self._effective_tree, ("plugins", plugin_name)) or {}
                 try:
-                    self._plugin_models[plugin_name] = schema(**plugin_data)
+                    new_plugins[plugin_name] = schema(**plugin_data)
                 except Exception as exc:
                     log.error(f"Failed to load configuration for plugin '{plugin_name}': {exc}")
-                    raise
+                    errors.append((name, exc))
                 continue
             if name == "plugins":
                 continue
             section_data = self._effective_tree.get(name, {})
             try:
-                self._section_models[name] = schema(**section_data)
+                new_sections[name] = schema(**section_data)
             except Exception as exc:
                 log.error(f"Failed to load configuration for section '{name}': {exc}")
-                raise
+                errors.append((name, exc))
+
+        if errors:
+            # propagate the first error; others already logged
+            raise errors[0][1]
+
+        self._section_models = new_sections
+        self._plugin_models = new_plugins
 
     def _get_model(self, name: str) -> Optional[BaseModel]:
         if name.startswith("plugins."):