feat: Docker Compose deployment + auto migration on startup

- docker-compose.yml: 移除 MySQL 容器，连宿主机 MySQL
- main.ts: 启动前通过独立 DataSource 执行 runMigrations
- migration-runner.ts: 独立 migration 执行器
- app.module.ts: TypeORM 配置增加 migrations
- 修复 InitialSchema 中 room_expenses 和 financial_operations 重复索引

apps/server/src/migration-runner.ts

@@ -0,0 +1,24 @@
+import { DataSource } from 'typeorm';
+import { InitialSchema1784520727860 } from './migrations/1784520727860-InitialSchema';
+import { config } from 'dotenv';
+
+config();
+
+const isMySQL = (process.env.DB_TYPE || 'sqlite') === 'mysql';
+
+export async function runMigrationsOnStartup(): Promise<void> {
+  const ds = new DataSource({
+    type: isMySQL ? 'mysql' : 'better-sqlite3',
+    host: isMySQL ? (process.env.DB_HOST || 'localhost') : undefined,
+    port: isMySQL ? Number(process.env.DB_PORT || 3306) : undefined,
+    username: isMySQL ? (process.env.DB_USERNAME || 'root') : undefined,
+    password: isMySQL ? (process.env.DB_PASSWORD || '') : undefined,
+    database: process.env.DB_DATABASE || (isMySQL ? 'dorm_billing' : 'dorm_billing.db'),
+    charset: isMySQL ? 'utf8mb4' : undefined,
+    migrations: [InitialSchema1784520727860],
+  });
+
+  await ds.initialize();
+  await ds.runMigrations();
+  await ds.destroy();
+}