class AppError(Exception):
    """Base error type for application-specific exceptions."""


class ConfigError(AppError):
    """Raised when configuration is invalid or missing."""


class InputValidationError(AppError):
    """Raised when input records fail validation."""


class LdapConnectionError(AppError):
    """Raised when LDAP connection or bind fails."""


class LdapOperationError(AppError):
    """Raised for LDAP operation failures."""


class StatePersistenceError(AppError):
    """Raised when state files cannot be read or written."""