wip: replace packages with pure files

packages/game/Stage.ts

@@ -0,0 +1,26 @@
+import { IStage } from './schema'
+import { StageException } from './Exception'
+import { Event } from './Event'
+
+export class Stage extends Event {
+  name: string
+  private exceptions: StageException[]
+
+  constructor({
+    id,
+    name,
+    condition,
+    requirements,
+    exceptions,
+    response,
+  }: IStage) {
+    super(id, condition, response, requirements)
+    this.name = name || ''
+    this.exceptions =
+      exceptions?.map((exception) => new StageException(exception)) || []
+  }
+
+  getExceptions(): StageException[] {
+    return this.exceptions
+  }
+}