fix(mail): save attachments for existing emails during sync

- IMAP sync now saves attachments for existing emails that have has_attachments=true
  but no attachment records in the database (retroactive attachment saving)
- Replace silent exception catching with logger.warning for attachment save failures
- Add logging module import and logger instance
- This fixes the issue where 62 emails had has_attachments=true but 0 attachment records

app/plugins/builtins/mail/services.py

@@ -4,6 +4,7 @@ from __future__ import annotations
 
 import base64
 import json
+import logging
 import mimetypes
 import os
 import re
@@ -39,6 +40,8 @@ from app.plugins.builtins.mail.models import (
     VacationSentLog,
 )
 
+logger = logging.getLogger(__name__)
+
 # ─── Attachment Storage Helpers ───
 
 MAX_ATTACHMENT_SIZE = 25 * 1024 * 1024  # 25 MB
@@ -754,6 +757,38 @@ async def imap_sync_account(
                         )
                     ).scalar_one_or_none()
                     if existing_mail:
+                        # Save attachments for existing emails that have has_attachments but no records
+                        if attachments and existing_mail.has_attachments:
+                            existing_att_count = (
+                                await db.execute(
+                                    select(text("COUNT(*)")).where(
+                                        and_(
+                                            MailAttachment.mail_id == existing_mail.id,
+                                            MailAttachment.tenant_id == tenant_id,
+                                        )
+                                    )
+                                )
+                            ).scalar() or 0
+                            if existing_att_count == 0:
+                                for att_data in attachments:
+                                    try:
+                                        storage_path = await _save_attachment_to_storage(
+                                            existing_mail.id, att_data["filename"], att_data["content"]
+                                        )
+                                        attachment = MailAttachment(
+                                            tenant_id=tenant_id,
+                                            mail_id=existing_mail.id,
+                                            filename=_sanitize_filename(att_data["filename"]),
+                                            mime_type=att_data["mime_type"],
+                                            size_bytes=att_data["size"],
+                                            storage_path=storage_path,
+                                            content_id=att_data.get("content_id"),
+                                        )
+                                        db.add(attachment)
+                                    except Exception as att_err:
+                                        logger.warning(f"Failed to save attachment for existing mail {existing_mail.id}: {att_err}")
+                                        continue
+                                await db.flush()
                         continue
 
                     mail = Mail(
@@ -801,8 +836,8 @@ async def imap_sync_account(
                                 content_id=att_data.get("content_id"),
                             )
                             db.add(attachment)
-                        except Exception:
-                            # Skip attachments that fail to save
+                        except Exception as att_err:
+                            logger.warning(f"Failed to save attachment for new mail {mail.id}: {att_err}")
                             continue
                     await db.flush()