fix(mail) : stop le spam GlitchTip de sync (double-encodage UTF7 + dossiers fantômes)

Deux causes racines généraient ~170 erreurs/cycle (toutes les 10 min) sur
la prod : "syncFolder[...] listMessages failed: Folder ... not found".

1. Double-encodage UTF7-IMAP : listFolders() stocke le chemin brut UTF7-IMAP,
   mais ImapMailProvider rappelait getFolder($path) qui ré-encode UTF8->UTF7-IMAP
   (webklex Client::getFolderByPath, utf7=false). Le caractère de shift "&" était
   ré-encodé, rendant introuvables les dossiers à accents/specials. Fix :
   getFolder($path, null, utf7: true) partout dans ImapMailProvider.

2. Dossiers fantômes jamais purgés : syncFolderStructure() gardait en DB les
   dossiers disparus du serveur, re-tentés à chaque cycle. Fix :
   syncFolderStructure() retourne le set des chemins présents sur le serveur ;
   doSyncAll() skip silencieusement les dossiers DB absents (conservés en DB
   pour les liens messages/tâches). Fallback historique si listFolders échoue.

Test : testSyncAllSkipsFoldersNoLongerPresentOnServer.

src/Module/Mail/Application/Service/MailSyncService.php

@@ -64,14 +64,22 @@ final class MailSyncService
         }
     }
 
-    public function syncFolderStructure(): void
+    /**
+     * Synchronise the local folder list with the server.
+     *
+     * @return null|array<string, true> the set of folder paths currently present
+     *                                  on the server, or null when the remote list
+     *                                  could not be fetched (the caller then falls
+     *                                  back to syncing every known folder)
+     */
+    public function syncFolderStructure(): ?array
     {
         try {
             $remoteFolders = $this->provider->listFolders();
         } catch (MailProviderException $e) {
             $this->logger->error('syncFolderStructure: listFolders failed: '.$e->getMessage());
 
-            return;
+            return null;
         }
 
         $remotePathSet = [];
@@ -95,16 +103,7 @@ final class MailSyncService
 
         $this->entityManager->flush();
 
-        $allDbFolders = $this->folderRepository->findAllOrderedByPath();
-
-        foreach ($allDbFolders as $dbFolder) {
-            if (!isset($remotePathSet[$dbFolder->getPath()])) {
-                $this->logger->warning(sprintf(
-                    'syncFolderStructure: folder "%s" no longer exists on server — keeping in DB for safety',
-                    $dbFolder->getPath()
-                ));
-            }
-        }
+        return $remotePathSet;
     }
 
     public function syncFolder(MailFolder $folder): MailSyncReport
@@ -259,7 +258,7 @@ final class MailSyncService
 
     private function doSyncAll(DateTimeImmutable $startedAt): MailSyncReport
     {
-        $this->syncFolderStructure();
+        $remotePathSet = $this->syncFolderStructure();
 
         $totalCreated = 0;
         $totalUpdated = 0;
@@ -270,6 +269,13 @@ final class MailSyncService
         $folders = $this->folderRepository->findAllOrderedByPath();
 
         foreach ($folders as $folder) {
+            // Skip folders that no longer exist on the server. They are kept in
+            // the DB (linked messages and tasks still reference them) but retrying
+            // listMessages every cycle only floods the logs with "Folder not found".
+            if (null !== $remotePathSet && !isset($remotePathSet[$folder->getPath()])) {
+                continue;
+            }
+
             try {
                 $report = $this->syncFolder($folder);
                 $totalCreated += $report->createdCount;

src/Module/Mail/Infrastructure/Imap/ImapMailProvider.php

@@ -103,7 +103,11 @@ final class ImapMailProvider implements MailProviderInterface
         $client = $this->getClient();
 
         try {
-            $folder = $client->getFolder($folderPath);
+            // Folder paths are stored exactly as the server returns them (raw
+            // UTF7-IMAP). Pass utf7: true so webklex matches them as-is instead of
+            // re-encoding UTF8 -> UTF7-IMAP, which double-encodes the "&" shift
+            // character and makes folders with accents/specials unresolvable.
+            $folder = $client->getFolder($folderPath, null, true);
             if (null === $folder) {
                 throw MailProviderException::operationFailed('listMessages', sprintf('Folder %s not found', $folderPath));
             }
@@ -138,7 +142,7 @@ final class ImapMailProvider implements MailProviderInterface
         $client = $this->getClient();
 
         try {
-            $folder = $client->getFolder($folderPath);
+            $folder = $client->getFolder($folderPath, null, true);
             if (null === $folder) {
                 throw MailProviderException::operationFailed('fetchMessage', sprintf('Folder %s not found', $folderPath));
             }
@@ -183,7 +187,7 @@ final class ImapMailProvider implements MailProviderInterface
         $client = $this->getClient();
 
         try {
-            $folder = $client->getFolder($folderPath);
+            $folder = $client->getFolder($folderPath, null, true);
             if (null === $folder) {
                 throw MailProviderException::operationFailed('markRead', sprintf('Folder %s not found', $folderPath));
             }
@@ -213,7 +217,7 @@ final class ImapMailProvider implements MailProviderInterface
         $client = $this->getClient();
 
         try {
-            $folder = $client->getFolder($folderPath);
+            $folder = $client->getFolder($folderPath, null, true);
             if (null === $folder) {
                 throw MailProviderException::operationFailed('markFlagged', sprintf('Folder %s not found', $folderPath));
             }
@@ -243,7 +247,7 @@ final class ImapMailProvider implements MailProviderInterface
         $client = $this->getClient();
 
         try {
-            $folder = $client->getFolder($folderPath);
+            $folder = $client->getFolder($folderPath, null, true);
             if (null === $folder) {
                 throw MailProviderException::operationFailed('moveMessage', sprintf('Folder %s not found', $folderPath));
             }
@@ -269,7 +273,7 @@ final class ImapMailProvider implements MailProviderInterface
         $client = $this->getClient();
 
         try {
-            $folder = $client->getFolder($folderPath);
+            $folder = $client->getFolder($folderPath, null, true);
             if (null === $folder) {
                 throw MailProviderException::operationFailed('fetchAttachment', sprintf('Folder %s not found', $folderPath));
             }