feat(mail): map standard IMAP folders per profile

src/govoplan_mail/backend/router.py

@@ -1179,6 +1179,7 @@ def _mailbox_folder_response(
         message=f"Found {len(folders)} IMAP folder(s).",
         folders=folders,
         detected_sent_folder=result.detected_sent_folder,
+        detected_folder_mappings=getattr(result, "detected_folder_mappings", None) or {},
         from_cache=from_cache,
         refreshing=refreshing,
         indexed_at=indexed_at,
@@ -2276,7 +2277,7 @@ def update_profile(
                 session,
                 profile=profile,
                 protocol="smtp",
-                config=smtp_config.model_dump(mode="json"),
+                config=smtp_config.model_dump(mode="json", exclude_none=True),
                 user_id=principal.user.id,
             )
         imap_server = None
@@ -2286,7 +2287,7 @@ def update_profile(
                 profile=profile,
                 protocol="imap",
                 config=(
-                    imap_config.model_dump(mode="json")
+                    imap_config.model_dump(mode="json", exclude_none=True)
                     if imap_config is not None and not payload.clear_imap
                     else None
                 ),
@@ -3063,6 +3064,7 @@ def list_imap_folder_settings(
             message=f"Found {len(folders)} IMAP folder(s).",
             folders=folders,
             detected_sent_folder=result.detected_sent_folder,
+            detected_folder_mappings=getattr(result, "detected_folder_mappings", None) or {},
         )
     except Exception as exc:
         return MailImapFolderListResponse(