refactor(profile): migrate reset user settings to new architecture
Replace the legacy ?act=reset include with a ResetSettingsController (POST /profile/{id}/reset-settings). Guard (rights>=7 and over a lower-rights user) is folded into GetResetSettingsContextUseCase; ResetUserSettingsUseCase performs the action via ProfileUserRepository::resetSettings, resetting set_user/set_forum through a loaded model so the casts serialize correctly. Convert the legacy edit.phtml link to a POST submit button and drop reset from the legacy dispatcher.