here goes nothin'

webui/src/lib/browserFingerprint.js

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+// Browser Fingerprint
+// Purpose: Wraps Thumbmark behind one app-owned helper so identity sync does not
+// depend on the third-party package shape throughout the UI.
+// Scope: Produces a normalized device fingerprint signal for the server identity service.
+import { getFingerprint } from '@thumbmarkjs/thumbmarkjs';
+
+let fingerprintPromise = null;
+
+function normalizeThumbmark(value) {
+  const raw = String(value || '').trim().toLowerCase();
+  if (!raw) return '';
+
+  /*
+    The server treats the prefix as part of the signal format so different
+    fingerprint providers can coexist later without hash-space ambiguity.
+  */
+  const body = raw.startsWith('tm_') ? raw.slice(3) : raw;
+  const safeBody = body.replace(/[^a-z0-9_-]/g, '');
+  return safeBody ? `tm_${safeBody}` : '';
+}
+
+export async function getBrowserFingerprintId() {
+  if (typeof window === 'undefined') return '';
+  if (!fingerprintPromise) {
+    fingerprintPromise = Promise.resolve()
+      .then(() => getFingerprint())
+      .then(normalizeThumbmark)
+      .catch((error) => {
+        console.warn('Failed to calculate browser fingerprint', error); // eslint-disable-line no-console
+        return '';
+      });
+  }
+  return fingerprintPromise;
+}