feat: the upload bar says how long is left, not a notice before it

The product page's notice about the upload time is gone. The cart's upload
bar now reads "Enviando seus arquivos · faltam cerca de 6 min", measured
from the upload's own speed (a range from the size for the first seconds),
with a line saying the time depends on the internet and to keep the page
open. The header and the pay button show the same time instead of a
percentage.

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

web/site-pdf.js

@@ -406,7 +406,6 @@ function detalhesDaFolha(a,i,aberto){
 }
 function pintaFolha(){
   invalidaItemAtual();
-  pintaAvisoEnvio();
   const L=larguraFilme();
   pintaTipoEnvio();                        // trava o seletor enquanto houver folha
   $('zona').classList.toggle('compacta', folhas.length>0);
@@ -529,7 +528,6 @@ function pintaProgressoArte(a){
 }
 function pintaArtes(){
   invalidaItemAtual();
-  pintaAvisoEnvio();
   $('zona').classList.toggle('compacta', artes.length>0);
   // The same card as a finished sheet: thumbnail, size, a DPI chip, then the
   // width (with the usual sizes), copies, rotation and mirroring.