feat(scripts): add Italian CEFR data pipeline

- Add extractors for Italian sources: it_m3.xls and italian.json
- Add comparison script (compare-italian.py) to report source overlaps and conflicts
- Add merge script (merge-italian-json.py) with priority order ['italian', 'it_m3']
- Output authoritative dataset to datafiles/italian-merged.json
- Update README to document both English and Italian pipelines

scripts/extraction-scripts/english/extract-en_m3.py

@@ -91,12 +91,12 @@ def extract() -> None:
     print(f"Extracted: {len(records)} records")
     print(f"  - Nouns: {noun_count}")
     print(f"  - Verbs: {verb_count}")
-    print(f"\nCEFR distribution:")
+    print("\nCEFR distribution:")
     for level in CEFR_LEVELS:
         if level in cefr_distribution:
             print(f"  - {level}: {cefr_distribution[level]}")
 
-    print(f"\nSkipped:")
+    print("\nSkipped:")
     print(f"  - Unsupported POS: {skipped_pos}")
     print(f"  - Invalid CEFR: {skipped_invalid_cefr}")
     print(f"  - Empty word: {skipped_empty_word}")