fix: improve login detection with fallback element (#493)

- Add fallback check for user-email element when mr-medium is not found
- Improve login detection reliability
- Add test case for alternative login element

tests/unit/test_init.py

@@ -324,6 +324,15 @@ class TestKleinanzeigenBotAuthentication:
         with patch.object(configured_bot, "web_text", return_value = "Welcome testuser"):
             assert await configured_bot.is_logged_in() is True
 
+    @pytest.mark.asyncio
+    async def test_is_logged_in_returns_true_with_alternative_element(self, configured_bot:KleinanzeigenBot) -> None:
+        """Verify that login check returns true when logged in with alternative element."""
+        with patch.object(configured_bot, "web_text", side_effect = [
+            TimeoutError(),  # First try with mr-medium fails
+            "angemeldet als: testuser"  # Second try with user-email succeeds
+        ]):
+            assert await configured_bot.is_logged_in() is True
+
     @pytest.mark.asyncio
     async def test_is_logged_in_returns_false_when_not_logged_in(self, configured_bot:KleinanzeigenBot) -> None:
         """Verify that login check returns false when not logged in."""