formulaire: correctifs identifiant/année, contact, fichiers optionnels

- Identifiant: mise à jour automatique quand l'année change en back-office (updateThesis + ThesisEditController)
- Contact: hint enrichi (1 seul contact, formatage Instagram/Mastodon)
- Fichiers: TFE rendu optionnel pour Site web/Performance/Installation (note d'intention reste obligatoire)

app/src/Database.php

@@ -2122,8 +2122,16 @@ class Database
             $this->fetchRow('theses', $thesisId)
         );
 
-        $stmt = $this->pdo->prepare('
+        $identifierCol = '';
+        $params = [];
+        if (array_key_exists('identifier', $data)) {
+            $identifierCol = 'identifier = ?,';
+            $params[] = $data['identifier'];
+        }
+
+        $stmt = $this->pdo->prepare("
             UPDATE theses SET
+                $identifierCol
                 title = ?,
                 subtitle = ?,
                 year = ?,
@@ -2144,7 +2152,7 @@ class Database
                 cc2r = ?,
                 updated_at = CURRENT_TIMESTAMP
             WHERE id = ?
-        ');
+        ");
         $orientation = ($data['orientation_id'] ?? null) ? (int)$data['orientation_id'] : null;
         $ap          = ($data['ap_program_id'] ?? null) ? (int)$data['ap_program_id'] : null;
         $finality    = ($data['finality_id'] ?? null) ? (int)$data['finality_id'] : null;
@@ -2153,7 +2161,7 @@ class Database
 
         error_log("[DB:updateThesis] thesis_id=$thesisId orientation=$orientation ap=$ap finality=$finality license=$license access=$access");
 
-        $stmt->execute([
+        $params = array_merge($params, [
             $data['title'],
             !empty($data['subtitle']) ? $data['subtitle'] : null,
             (int)$data['year'],
@@ -2174,6 +2182,7 @@ class Database
             !empty($data['cc2r']) ? 1 : 0,
             $thesisId,
         ]);
+        $stmt->execute($params);
     }
 
     /**