feat(ui): load request covers through the local cache

static/app.js

@@ -81,6 +81,11 @@ function libOptions(mediaType) {
     .join("");
 }
 
+// the server keeps a copy; the url in the query makes a changed cover a new address
+function coverSrc(r) {
+  return `/api/requests/${r.id}/cover?u=${encodeURIComponent(r.cover_url)}`;
+}
+
 // ---- missing badge ----
 async function refreshMissingBadge() {
   try {
@@ -609,7 +614,7 @@ function renderRequests(status) {
   box.innerHTML = reqs
     .map(
       (r) => `<div class="card clickable" data-detail="${r.id}" tabindex="0">
-        ${r.cover_url ? `<img src="${esc(r.cover_url)}" alt="" loading="lazy">` : '<div class="nocover">?</div>'}
+        ${r.cover_url ? `<img src="${esc(coverSrc(r))}" alt="" loading="lazy">` : '<div class="nocover">?</div>'}
         <div class="card-body">
           <strong>${esc(r.title)}${r.volume != null ? ` · ${t("common.volume")} ${r.volume}` : ""}</strong>
           <span>${esc(r.authors)}</span>
@@ -888,7 +893,7 @@ function openDetail(id, status) {
   const img = $("#detail-cover");
   img.hidden = !r.cover_url;
   $("#detail-nocover").hidden = !!r.cover_url;
-  if (r.cover_url) img.src = r.cover_url;
+  if (r.cover_url) img.src = coverSrc(r);
   $("#detail-retag").hidden = !(r.status === "imported" && r.media_type === "audiobook");
   $("#detail-relocate").hidden = r.status !== "imported";
   $("#detail-dialog").showModal();