refactor(data-schemas): introduce new models and types for balance, conversation, message, and session

- Added new model files for Balance, Conversation, Message, and Session, enhancing modularity.
- Created corresponding type definitions for IBalance, IConversation, IMessage, and updated existing types.
- Refactored index files to export models from their individual files for better organization.

packages/data-schemas/src/models/message.ts

@@ -0,0 +1,16 @@
+import mongoose from 'mongoose';
+import mongoMeili from '~/models/plugins/mongoMeili';
+import messageSchema from '~/schema/message';
+import type * as t from '~/types';
+
+if (process.env.MEILI_HOST && process.env.MEILI_MASTER_KEY) {
+  messageSchema.plugin(mongoMeili, {
+    host: process.env.MEILI_HOST,
+    apiKey: process.env.MEILI_MASTER_KEY,
+    indexName: 'messages',
+    primaryKey: 'messageId',
+  });
+}
+
+export const Message =
+  mongoose.models.Message || mongoose.model<t.IMessage>('Message', messageSchema);