• Reduced reflection decoding time and memory allocations. A city-lookup benchmark
  decoding a geoip2-style result allocates 20% fewer bytes (saving 48 B/op) and
  2 fewer heap allocations per lookup when utilizing pointer-heavy destination
  structures.
• Optimized map key decoding by adding a fast path for pointer keys, improving
  general lookup throughput by 2.7% to 6.4%.
• Optimized tree traversal for IPv6 lookups, resulting in an ~8.8% speedup.
• Fixed pointer-to-pointer chains in malformed database data so decoder entry
  points reject them consistently instead of following invalid chains.
• Reduced memory mapping overhead and system allocations when invoking OpenBytes
  and NetworksWithin.
• Cleaned up, simplified, and deduplicated internal decoder and reader structures,
  removing deprecated type assertion workarounds and unused helper functions.