feat: add auth to tui

apps/tui/util/qr.ts

@@ -0,0 +1,26 @@
+import QRCode from "qrcode";
+
+export function QR(value: string): string {
+  const qr = QRCode.create(value, {
+    errorCorrectionLevel: "L",
+    version: 3,
+  });
+
+  const m = qr.modules.data;
+  const size = qr.modules.size;
+
+  // Use half-block characters to compress vertically
+  // Upper half = '▀', lower half = '▄', full = '█', empty = ' '
+  let out = "";
+  for (let y = 0; y < size; y += 2) {
+    for (let x = 0; x < size; x++) {
+      const top = m[y * size + x];
+      const bottom = m[(y + 1) * size + x];
+      out += top && bottom ? "█" : top ? "▀" : bottom ? "▄" : " ";
+    }
+    out += "\n";
+  }
+  return out;
+}
+
+