fix typo

app.py

@@ -78,7 +78,7 @@ def process_ocr_qa(text, lang_choice):
                 # Unknown tokens (potential OCR errors)
                 if 'unknown_tokens' in diagnostics and diagnostics['unknown_tokens']:
                     unknown_tokens = diagnostics['unknown_tokens']
-                    output_lines.append(f"❌ Unrecognized unique tokens (u}):\n{' '.join(unknown_tokens)}")
+                    output_lines.append(f"❌ Unrecognized unique tokens ({u}):\n{' '.join(unknown_tokens)}")
                 elif 'unknown_tokens' in diagnostics:
                     output_lines.append("✨ All tokens were known – no OCR errors detected.")