fix: pin gradio>=4.44.1, modernize typing, clean ruff lint

feat(data): add 20 sparse-label synthetic generators; dataset now 90 222 rows

fix: remove duplicate-tail dead code; harmonise app label vocabulary

feat: expand to 81 ciphers — improved heuristic, 12 new cipher generators, focal-loss training

ADA/mobile UI, pytest pythonpath, train_transformer PyArrow fix, enriched Explain Mode

10/10 polish: Compare Mode, Kasiski/Friedman, rich dataset schema, expanded tests/docs

Initial Cipher Detective AI public foundation