Janis
3437dab49b
Adds optional multithreaded search behind a thread count that defaults to 1, so the live bot's play is unchanged until explicitly configured. - ParallelSearch runs N AlphaBetaSearch workers over one shared, already-lock-protected TranspositionTable. Each worker has its own NNUE evaluator (independent accumulator) and ordering state; helpers only deepen the shared TT, the main worker's move is returned. - AlphaBetaSearch gains bestMoveWithTimeSharedTt: the coordinator clears the shared TT once before launching workers, so helpers must not clear. - EvaluationNNUE.freshEvaluator builds independent evaluators sharing the immutable weights (one per thread); the singleton still backs the default single-instance path. - NNUEBot uses ParallelSearch with NNUE_SEARCH_THREADS (default 1). numThreads <= 1 takes the single-worker clearing path, identical to the previous sequential search. Strength can be validated by self-play (threads N vs 1) before promoting the default. Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>