feat: refactor quest models

+ separate stage and exception
+ reuse commandResponder

packages/models/response.js

@@ -0,0 +1,15 @@
+import { Schema } from 'mongoose'
+
+const responseSchema = new Schema({
+  type: {
+    type: String,
+    enum: ['narrative', 'dialogue'],
+    default: 'dialogue',
+    required: true,
+  },
+  content: [String],
+  speaker: { type: String, default: 'Ada' },
+  color: String,
+})
+
+export default responseSchema