Rarog 2.0.1

Patch release focused on search strength, time management, and release build reliability.

Added

• Added Internal Iterative Reduction for PV nodes when no usable transposition-table move is available.
• Added TT PV-node tracking so pruning and reductions can treat PV-touched nodes more carefully.
• Added history-based capture pruning for losing captures.
• Added negative capture-history updates for good captures searched before a beta cutoff.
• Added correction-history updates for Lower and Upper bound nodes, not only Exact/PV nodes.
• Added a light simple logo asset alongside the dark variant.
• Added regression coverage for short movetime searches, long endgame searches, and long reversible games.

Changed

• Improved aspiration windows with exponential widening after fail-high or fail-low results.
• Increased correction-history table size from 16k to 64k entries.
• Unified capture-history beta-cutoff bonus with the quiet-history bonus formula.
• Extended singular extensions to depth 4 and above.
• Extended quiet-history pruning to depth 7.
• Improved LMR re-search node-type handling.
• Parallelized transposition-table clear operations.
• Increased engine and search worker thread stack sizes to avoid stack overflow in deeper tactical/endgame searches.
• Improved time management by avoiding a new iteration when the previous iteration suggests it may overrun the hard time limit.
• Hardened PGO release training with bench timeouts and child-process cleanup.

Fixed

• Fixed short fixed-time searches so go movetime 100 completes at least depth 1 before returning bestmove.
• Fixed a long-game board-history limit by restoring dynamically growing move history.
• Fixed TT PV flag handling so PV status is not incorrectly preserved across overwritten entries.
• Fixed release PGO training so a stuck or incomplete bench run fails cleanly instead of hanging.