Function checkMigrationNeeded

checkMigrationNeeded(
    d1: D1Database,
    shardName: string,
    config: CollegeDBConfig,
): Promise<boolean>
Performs a lightweight check to determine if a database contains existing data that hasn't been mapped to the sharding system. This is used internally to trigger automatic migration.
Parameters
- d1: D1Database
  The D1 database instance to check
- shardName: string
  The shard binding name
- config: CollegeDBConfig
  CollegeDB configuration
Returns Promise<boolean>
Promise resolving to true if migration is needed
Example
```
const needsMigration = await checkMigrationNeeded(env.DB, 'db-main', config);
if (needsMigration) {
  console.log('Database contains unmapped data');
}
```
- Defined in migrations.ts:784