Increase LMR when TT move is a capture

[KnightStackSys]

Adds an isolated LMR experiment based on current main.

Change

When a move is already LMR-eligible (late quiet move), add one extra ply of reduction if the node's TT move is a capture:

if (ttMove && ttMove.isCapture())
    ++reduction;

Rationale

A tactical TT move can be a signal that late quiet alternatives are less likely to be competitive, so this experiment reduces those quiet moves more aggressively while preserving the existing full-depth re-search when a reduced search beats alpha.

Scope

• based on main
• only src/search.cpp changes
• TT move itself is not affected because LMR only applies to quiet moves here
• captures/promotions are not newly reduced
• no changes to base LMR table, PVS, TT policy, move ordering, pruning, evaluation, or history updates

For clean testing, SPRT this branch directly against main.