fix: quote freight on its own, and drop the Calcular button

Going back to home delivery with a CEP already typed, or restoring a saved
cart, now quotes the freight again by itself; before, only pressing Calcular
did. With every case covered, the button is gone.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

web/index.html

@@ -1170,8 +1170,7 @@ footer a:hover{color:var(--laranja2)}
           <div class="cep" id="cep">
             <label>CEP de entrega</label>
             <div class="cepL">
-              <input id="cepIn" inputmode="numeric" maxlength="9" placeholder="00000-000">
-              <button id="bCep">Calcular</button>
+              <input id="cepIn" inputmode="numeric" maxlength="9" placeholder="00000-000" autocomplete="postal-code">
             </div>
             <p id="cepMsg"></p>
             <div class="campos endereco" id="endereco">