frontend search input validation

contracts/templates/contracts/search.html

@@ -32,7 +32,8 @@
                 id="signing_party_ico_number"
                 name="signing_party_ico_number"
                 class="border border-black bg-grey-150 h-10 px-4 text-lg xl:h-14 xl:px-5"
-                type="text"
+                type="number"
+                min="0"
                 value="{% if signing_party_ico_number %}{{ signing_party_ico_number }}{% endif %}"
                 placeholder="IČO smluvních stran"
                 aria-label="Vyhledávací box pro IČO smluvních stran"