Feature: Settings coverage boost
  Additional scenarios that exercise previously uncovered code paths
  in the Settings class (settings.py lines 561-563 and 602-611).

  Background:
    Given the settings coverage module is imported

  Scenario: Model validator rejects retry_max_delay less than retry_base_delay
    When I create Settings with retry_max_delay less than retry_base_delay
    Then a ValidationError should be raised about delay ordering
    And the error message should mention both delay values

  Scenario: repr masks sensitive field values when set
    Given I have a Settings instance with openai_api_key set to a secret value
    When I call repr on the settings instance
    Then the repr output should contain REDACTED for the openai_api_key field
    And the repr output should start with "Settings(" and end with ")"

  Scenario: repr shows non-sensitive fields normally
    Given I have a Settings instance with default values
    When I call repr on the settings instance
    Then the repr output should contain the env field with its actual value
    And the repr output should not contain REDACTED for non-sensitive fields

  Scenario: repr shows REDACTED only for non-None sensitive keys
    Given I have a Settings instance where all sensitive keys are None
    When I call repr on the settings instance
    Then the repr output should show None for sensitive key fields without redaction