What common mistake do developers make with Database directory, why does the mistake cause problems, and what is the safer approach?

What common mistake do developers make with Database directory, why does the mistake cause problems, and what is the safer approach? One recurring problem with database directory is applying it without understanding the boundary it protects. Putting application secrets or manually edited runtime files inside source directories instead of using environment configuration and framework-managed storage. In addition, The database directory contains migrations, seeders, factories and related database-development files. Safer engineering approach: keep the responsibility in the correct layer, use the framework's supported API, validate and authorize inputs, avoid hidden side effects, and verify the behavior with tests.