Feature: TUI Persona Schema Coverage
  Scenarios that exercise uncovered code paths in
  cleveragents.tui.persona.schema (lines 39, 66, 68, 73-82).

  Background:
    Given the persona schema module is imported

  # --- Validator: actor must contain "/" (line 39) ---

  Scenario: Creating a Persona with an un-namespaced actor raises ValueError
    When I create a Persona with actor "plain_actor"
    Then tpschcov a ValueError should be raised with message containing "actor must be namespaced"

  # --- Model validator: exactly one default preset (line 66) ---

  Scenario: Multiple default presets raises ValueError
    When I create a Persona with two default presets
    Then tpschcov a ValueError should be raised with message containing "must contain exactly one default preset"

  Scenario: Zero default presets when presets are provided raises ValueError
    When I create a Persona with presets but no default preset
    Then tpschcov a ValueError should be raised with message containing "must contain exactly one default preset"

  # --- Model validator: default preset overrides must be empty (line 68) ---

  Scenario: Default preset with non-empty overrides raises ValueError
    When I create a Persona whose default preset has overrides
    Then tpschcov a ValueError should be raised with message containing "default preset overrides must be empty"

  # --- effective_arguments: no preset name returns base_arguments (lines 73-75) ---

  Scenario: effective_arguments without a preset name returns base arguments
    Given I have a valid Persona with base arguments
    When I call effective_arguments with no preset name
    Then the result should equal the base arguments

  # --- effective_arguments: unknown preset name returns base_arguments (lines 76-80) ---

  Scenario: effective_arguments with an unknown preset name returns base arguments
    Given I have a valid Persona with base arguments
    When I call effective_arguments with preset name "nonexistent"
    Then the result should equal the base arguments

  # --- effective_arguments: known preset merges overrides (lines 76-77, 81-82) ---

  Scenario: effective_arguments with a known preset merges overrides onto base
    Given I have a valid Persona with base arguments and a custom preset
    When I call effective_arguments with preset name "fast"
    Then the result should contain the base arguments merged with the preset overrides