admin/parametres: cleanup page — remove card syntax, use semantic HTML (checkboxes/fieldsets), move delete-all-TFE danger zone into maintenance

src/Database.php

@@ -1659,6 +1659,17 @@ class Database {
         return (string)$row['identifier'];
     }
 
+    /**
+     * Delete every thesis in the database.
+     */
+    public function deleteAllTheses(): int {
+        $ids = $this->pdo->query("SELECT id FROM theses")->fetchAll(\PDO::FETCH_COLUMN);
+        if (empty($ids)) return 0;
+        $count = count($ids);
+        $this->bulkDeleteTheses($ids);
+        return $count;
+    }
+
     /**
      * Insert a thesis file record
      */