Report every failed fetch instead of discarding it

Twenty-four fetch chains ended in an empty catch, which is not error handling
but error deletion: the request fails, nothing renders, nothing is logged, and
the surface sits on Loading forever. That is how the mesh chat's ReferenceError
read as a slow load for as long as it did.

Plugin/unraid/Varaverk.page

@@ -92,6 +92,37 @@ function vvEscAttr(s) {
                         .replace(/</g,'&lt;').replace(/>/g,'&gt;');
 }
 
+// ═══════════════════════════════════════════════════════════════════════════════════════════════
+// What a failed fetch says.
+//
+// Every fetch in this plugin used to end in `.catch(() => {})` — 24 of them. That is not error
+// handling, it is error deletion: the request fails, nothing renders, nothing is logged, and the
+// surface either sits on "Loading…" forever or silently keeps showing stale numbers. The mesh chat
+// spent an unknown amount of time "taking a minute to load" because a ReferenceError was thrown on
+// every render and swallowed here; the fault named itself the moment a catch reported it.
+//
+// Console always, because a poller that drops one tick should not shout on screen. A target
+// element when the caller has one, because a panel that will otherwise never fill has to say why.
+//
+// Global for the same reason vvEscHtml is: pages/*.php are included one at a time and each would
+// otherwise carry its own copy, which is the arrangement that lets two of them drift.
+function vvFetchErr(where, e, el) {
+  const msg = (e && e.message) ? e.message : String(e || 'request failed');
+  try { console.warn('[varaverk] ' + where + ' — ' + msg, e); } catch (_) {}
+  if (el) {
+    const n = (typeof el === 'string') ? document.getElementById(el) : el;
+    if (n) { n.textContent = where + ' failed: ' + msg; n.style.color = '#a05a2c'; }
+  }
+}
+
+// Throws on a non-2xx instead of handing HTML to JSON.parse. Unraid answers an expired session
+// with a 302 to the login page, so without this the reported error is "Unexpected token '<'",
+// which names the symptom and hides the cause.
+function vvJson(r) {
+  if (!r.ok) throw new Error('HTTP ' + r.status);
+  return r.json();
+}
+
 // A URL about to be put in href/src or handed to window.open. Anything that is not plainly http,
 // https or a site-relative path becomes empty — javascript: is the one that matters, and an
 // allowlist is the only way to say that without chasing encodings. include/docs.php applies the