v2.0 - Improved library learning with diversity enforcement

- Tree similarity metrics to prevent duplicate patterns
- Quality scoring with complexity penalties
- Fitness threshold filtering (top 20%)
- Competitive pruning of low-value library entries
- Increased update frequency and pattern extraction

Library now maintains 13 diverse patterns instead of 31 duplicates.
Slight fitness improvement on Taxi-v3 (-192 to -189).

v1.0 - Initial release

- Tree-based GP with typed operations
- Multi-threaded fitness evaluation (9x speedup)
- Memory operations (MEM_READ/WRITE)
- Library learning system
- Solves: addition, CartPole, maze navigation
- Partial: Taxi-v3