Add keli and keskiarvo to public kokeet listing

[asku1990]

Current public trials listing is missing two fields that existed in the old v1 KOKEET kalenterivuosittain view: Keli and Keskiarvo.

Please compare against the old model before changing anything:

• ../beagleAppV1/kokeetall.php
• ../beagleAppV1/hallinta/ad_kokeetall.php

What to verify in v1:

• The listing columns include Koepaikka, Päivä, Keli, Koiria kokeessa, and Keskiarvo.
• The old UI has the Koepaikkakunnittain and Koirat aakkosjärjestyksessä modes, but the key parity gap here is the basic public list showing weather and average.
• Check how the old page derives Keli and Keskiarvo from the trial data model so the new implementation matches the original intent.

Implementation goal:

• Add keli and keskiarvo to the public basic listing in the v2 app.
• Keep the change focused on the listing only unless the old source shows a broader shared data-shaping requirement.

Suggested acceptance criteria:

• Public trial listing shows Keli and Keskiarvo in the basic results view.
• Mobile and desktop presentations stay consistent.
• The values match the old v1 meaning, not a new interpretation.
• Add/update tests for the list rendering and any data mapping needed.