Settings → MAILBOXES: удалить ящик вместе с письмами

DELETE /api/admin/mailboxes/{id} (только администратор, не свой ящик):
файлы вложений, затем строка users — папки, письма, исходники, контакты,
участие в рассылках и доступы уходят каскадом. Кнопка с подтверждением.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

backend/src/main/java/com/mailserver/controller/MailboxAdminController.java

@@ -158,6 +158,19 @@ public class MailboxAdminController {
         }))).flatMap(this::view);
     }
 
+    /** Deleted for good with all its mail (Settings → MAILBOXES → Delete); not your own mailbox. */
+    @DeleteMapping("/{id}")
+    @ResponseStatus(HttpStatus.NO_CONTENT)
+    public Mono<Void> delete(Mono<Authentication> auth, @PathVariable Long id) {
+        return admin(auth).flatMap(me -> mailbox(id).flatMap(user -> {
+            if (user.getEmail().equalsIgnoreCase(me)) {
+                return Mono.error(bad("You can not delete your own mailbox"));
+            }
+            return mail.deleteMailbox(user)
+                    .doOnSuccess(v -> log.warn("Mailbox {} deleted with all its mail by administrator {}", user.getEmail(), me));
+        }));
+    }
+
     /** Trap: what the mailbox sends is stored in its own INBOX, nothing leaves the server (staging@). */
     @PutMapping("/{id}/trap")
     public Mono<MailboxView> trap(Mono<Authentication> auth, @PathVariable Long id, @RequestBody Mono<TrapRequest> body) {

backend/src/main/java/com/mailserver/repository/AttachmentRepository.java

@@ -12,6 +12,10 @@ public interface AttachmentRepository extends R2dbcRepository<Attachment, Long>
 
     Mono<Long> countByMessageId(Long messageId);
 
+    /** All attachments of a mailbox — their files are removed with the mailbox. */
+    @Query("SELECT a.* FROM attachments a JOIN messages m ON m.id = a.message_id JOIN folders f ON f.id = m.folder_id WHERE f.user_id = :#{#userId}")
+    Flux<Attachment> findByMailbox(Long userId);
+
     @Modifying
     @Query("UPDATE attachments SET message_id = :#{#to} WHERE message_id = :#{#from}")
     Mono<Integer> moveAll(Long from, Long to);

backend/src/main/java/com/mailserver/service/MailService.java

@@ -401,6 +401,16 @@ public class MailService {
                 .then(messageRepository.delete(message));
     }
 
+    /**
+     * Mailbox deleted for good: attachment files first, then the user row — folders, messages, sources, contacts,
+     * list memberships and access rows go with it (ON DELETE CASCADE).
+     */
+    public Mono<Void> deleteMailbox(User user) {
+        return attachmentRepository.findByMailbox(user.getId())
+                .doOnNext(attachment -> deleteFile(attachment.getFilePath()))
+                .then(userRepository.delete(user));
+    }
+
     private static void deleteFile(String path) {
         try {
             Files.deleteIfExists(Paths.get(path));