Implement and tune Lazy SMP search

[alfooscxx]

Supersedes #44 and brings the merged #45 stack to master.

Summary:

• fix null move pruning conditions
• add UCI Threads support with Lazy SMP workers sharing a clustered lock-free transposition table
• make TT capacity configurable with mmap-backed large tables and transparent huge-page advice
• expose and tune RFP, NMP, IIR, and LMR search parameters
• add automated tuning, strength-evidence, transposition-table, and UCI lifecycle tests
• ensure the test target builds the engine required by the UCI lifecycle test

Validation:

• 130/130 enabled regression tests passed in GCC 15
• both CI checks passed on the merged integration tip
• the pre-existing disabled NMP fixture and long WinAtChess test remain excluded