feat: email retry page on 550 rejection; confirmation_email optional in admin form

app/src/Controllers/ThesisCreateController.php

@@ -325,14 +325,13 @@ class ThesisCreateController
             }
         }
 
-        // Confirmation e-mail (required)
+        // Confirmation e-mail (optional)
         $confirmationEmail = trim($post['confirmation_email'] ?? '');
-        if ($confirmationEmail === '') {
-            throw new Exception("L'adresse e-mail de confirmation est requise.");
-        }
-        $confirmationEmail = filter_var($confirmationEmail, FILTER_VALIDATE_EMAIL);
-        if ($confirmationEmail === false) {
-            throw new Exception("L'adresse e-mail de confirmation n'est pas valide.");
+        if ($confirmationEmail !== '') {
+            $confirmationEmail = filter_var($confirmationEmail, FILTER_VALIDATE_EMAIL);
+            if ($confirmationEmail === false) {
+                throw new Exception("L'adresse e-mail de confirmation n'est pas valide.");
+            }
         }
 
         return compact(

app/src/Dispatcher.php

@@ -122,6 +122,13 @@ class Dispatcher {
             };
         }
 
+        // /partage/retry-email  (GET: show retry form, POST: resend)
+        if ($path === '/partage/retry-email') {
+            return function() {
+                require APP_ROOT . '/public/partage/retry-email.php';
+            };
+        }
+
         // /partage/*
         if (preg_match('#^/partage(/.*)?$#', $path)) {
             return function() {

app/src/StudentEmail.php

@@ -102,9 +102,8 @@ class StudentEmail {
         try {
             $result = SmtpRelay::send($db, $to, $subject, $htmlBody);
         } catch (SmtpSendException $e) {
-            // Confirmation email failure must not abort the successful submission.
             error_log("[StudentEmail] SMTP error sending to {$to} for thesis #{$thesisId}: " . $e->getMessage());
-            return false;
+            throw $e;  // re-throw so callers can react (e.g. redirect to retry page)
         }
 
         if ($result) {