Feature: User preferences (theme)
  As a signed-in user
  I want to switch between system/light/dark theme
  So that the app matches my preference, applied immediately

  Background:
    Given I am signed in as "Alice" "Martin"

  Scenario: Shows SYSTEM selected by default
    Given my saved theme preference is "SYSTEM"
    When I visit "/parametres/preferences-utilisateur"
    Then the radio "Système" should be checked
    And the radio "Clair" should not be checked
    And the radio "Sombre" should not be checked
    And the page should have no theme override

  Scenario: Shows the previously saved theme selected, and applies it to the document
    Given my saved theme preference is "DARK"
    When I visit "/parametres/preferences-utilisateur"
    Then the radio "Sombre" should be checked
    And the page theme should be "dark"

  Scenario: Switching theme autosaves and applies immediately, no explicit save button
    Given my saved theme preference is "SYSTEM"
    And updating the theme preference will succeed
    When I visit "/parametres/preferences-utilisateur"
    Then I should not see "Enregistrer"
    When I click the radio "Clair"
    Then the theme update request should have been made with theme "LIGHT"
    And I should see "Enregistré ✓"
    And the page theme should be "light"