Set tstamp on record inserts/updates

Questions, editor assignments and conditions were inserted without tstamp,
so Contao rendered them with tstamp=0 -> the backend "draft" styling
(opacity .5), making question rows look greyed out despite being published.

- SurveyQuestionRepository::insert()/update() (covers create, edit, duplicate)
- SurveyEditorRepository::insert()
- SurveyConditionRepository::insert()
SurveyRepository already set tstamp. Also widened the assigned-members
checkbox-wizard columns at smaller breakpoints.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

src/Repository/SurveyConditionRepository.php

@@ -62,6 +62,7 @@ final class SurveyConditionRepository
     {
         $this->connection->insert('tl_survey_condition', [
             'pid' => $surveyId,
+            'tstamp' => time(),
             'sourceQuestion' => (int) ($data['sourceQuestion'] ?? 0),
             'answerValue' => mb_strtolower(trim((string) ($data['answerValue'] ?? ''))),
             'targetQuestion' => (int) ($data['targetQuestion'] ?? 0),