fix(auth): reject invalid bearer tokens instead of falling back

Modify the authentication handler to return an unauthorized error when
an invalid or disabled bearer token is provided, rather than silently
falling back to an anonymous request.

This ensures that clients attempting to authenticate but failing (due to
expired, malformed, or disabled tokens) are explicitly notified of the
auth failure instead of proceeding anonymously. True anonymous requests
without any Authorization header remain supported.

backend/static/js/00-utils.js

@@ -0,0 +1,62 @@
+(function () {
+  window.Warpbox = window.Warpbox || {};
+
+  window.Warpbox.openInNewTab = function openInNewTab(url) {
+    window.open(url, "_blank", "noopener,noreferrer");
+  };
+
+  window.Warpbox.writeClipboard = async function writeClipboard(text) {
+    if (navigator.clipboard && window.isSecureContext) {
+      await navigator.clipboard.writeText(text);
+      return;
+    }
+
+    const textarea = document.createElement("textarea");
+    textarea.value = text;
+    textarea.setAttribute("readonly", "");
+    textarea.style.position = "fixed";
+    textarea.style.opacity = "0";
+    document.body.append(textarea);
+    textarea.select();
+    document.execCommand("copy");
+    textarea.remove();
+  };
+
+  window.Warpbox.copyText = async function copyText(text, button, copiedLabel) {
+    if (!text || !button) {
+      return;
+    }
+    await window.Warpbox.writeClipboard(text);
+    const previous = button.textContent;
+    button.textContent = copiedLabel;
+    setTimeout(() => {
+      button.textContent = previous;
+    }, 1400);
+  };
+
+  window.Warpbox.formatDate = function formatDate(value) {
+    const date = new Date(value);
+    if (Number.isNaN(date.getTime())) {
+      return value;
+    }
+    return date.toLocaleDateString(undefined, {
+      month: "short",
+      day: "numeric",
+      year: "numeric",
+    });
+  };
+
+  window.Warpbox.formatBytes = function formatBytes(bytes) {
+    if (bytes < 1024) {
+      return `${bytes} B`;
+    }
+    const units = ["KiB", "MiB", "GiB", "TiB"];
+    let value = bytes / 1024;
+    let unit = 0;
+    while (value >= 1024 && unit < units.length - 1) {
+      value /= 1024;
+      unit += 1;
+    }
+    return `${value.toFixed(1)} ${units[unit]}`;
+  };
+})();