feat(mail): map standard IMAP folders per profile

tests/test_imap_parser.py

@@ -8,6 +8,7 @@ from govoplan_mail.backend.config import ImapConfig
 from govoplan_mail.backend.sending.imap import (
     ImapAppendError,
     ImapConfigurationError,
+    _detect_standard_folder_mappings,
     _detect_sent_folder,
     _extract_mailbox_name,
     _fetch_message_by_uid,
@@ -18,6 +19,7 @@ from govoplan_mail.backend.sending.imap import (
     _select_readonly,
     _sequence_set,
     append_message_to_sent,
+    list_imap_folders,
     list_imap_messages,
     list_imap_uids_since,
 )
@@ -79,6 +81,45 @@ class ImapFolderParserTests(unittest.TestCase):
             "Gesendet",
         )
 
+    def test_detects_all_standard_folder_roles_by_flag_then_name(self):
+        self.assertEqual(
+            {
+                "inbox": "INBOX",
+                "sent": "Gesendete Elemente",
+                "drafts": "Entwürfe",
+                "trash": "Deleted",
+                "archive": "All Mail",
+                "junk": "Spam",
+            },
+            _detect_standard_folder_mappings(
+                [
+                    ("INBOX", set()),
+                    ("Gesendete Elemente", set()),
+                    ("Entwürfe", set()),
+                    ("Deleted", {"\\trash"}),
+                    ("All Mail", {"\\all"}),
+                    ("Spam", {"\\junk"}),
+                ]
+            ),
+        )
+
+    def test_mock_folder_listing_exposes_detected_standard_mappings(self):
+        result = list_imap_folders(
+            imap_config=ImapConfig(host="mock.imap.local"), include_status=False
+        )
+
+        self.assertEqual(
+            {
+                "inbox": "INBOX",
+                "sent": "Sent",
+                "drafts": "Drafts",
+                "trash": "Trash",
+                "archive": "Archive",
+            },
+            result.detected_folder_mappings,
+        )
+        self.assertEqual("Sent", result.detected_sent_folder)
+
 
 class ImapMessagePaginationTests(unittest.TestCase):
     def test_mock_message_cursor_preserves_order_and_resets_when_stale(self):

tests/test_mail_profile_helpers.py

@@ -290,6 +290,51 @@ class MailProfileTransportHelperTests(unittest.TestCase):
         self.assertEqual(audit.call_args.kwargs["details"]["protocol"], "imap")
         self.assertNotIn("imap-secret", repr(audit.call_args.kwargs))
 
+    def test_apply_transport_update_persists_standard_folder_mappings(self):
+        profile = SimpleNamespace(
+            id="profile-folders",
+            tenant_id="tenant-1",
+            scope_type="tenant",
+            scope_id="tenant-1",
+            smtp_config={"host": "smtp.example.org"},
+            smtp_username=None,
+            smtp_password_encrypted=None,
+            smtp_transport_revision="smtp-before",
+            imap_config={"host": "imap.example.org", "sent_folder": "Legacy Sent"},
+            imap_username=None,
+            imap_password_encrypted=None,
+            imap_transport_revision="imap-before",
+        )
+        session = SimpleNamespace(flush=lambda: None)
+
+        with patch("govoplan_mail.backend.mail_profiles.clear_mailbox_index"):
+            _apply_profile_transport_update(
+                session,  # type: ignore[arg-type]
+                profile,
+                user_id="user-1",
+                api_key_id=None,
+                smtp=None,
+                imap=ImapConfig(
+                    host="imap.example.org",
+                    folder_mappings={
+                        "inbox": "INBOX",
+                        "sent": "Sent Items",
+                        "drafts": "Drafts",
+                    },
+                ),
+                clear_imap=False,
+            )
+
+        self.assertEqual(profile.imap_config["sent_folder"], "Sent Items")
+        self.assertEqual(
+            profile.imap_config["folder_mappings"],
+            {
+                "inbox": "INBOX",
+                "sent": "Sent Items",
+                "drafts": "Drafts",
+            },
+        )
+
     def test_imap_password_replacement_clears_cache_without_rotating_identity_revision(self):
         profile = SimpleNamespace(
             id="profile-1",