Eval.c diet: kill exact-duplicate terms, turn down overlapping ones, fix a real king-safety bug found along the way.

A full-file pass over eval.c hunting for the "positional terms too
loud" feedback from real chess programmers, following the concrete
finding that Crafty prices most structural themes through one term
where this codebase spread the same theme across several (passed
pawns alone via 5-6 separate additive terms that can all fire for one
pawn). Two categories of fix, applied per the rule "if it's counting
the same thing twice, kill it; if it's a genuinely different angle on
the same theme, turn it down rather than remove it":

Pawns (pawn-hash cached, so free regardless of term count -- these are
data/magnitude fixes, not perf fixes):
  - Removed ISOLATED_PAWN_PENALTY_BY_COUNT, a whole-position aggregate
    that re-priced the same uIsolated[] count already reflected by
    summing the per-pawn isolated term once per isolated pawn -- an
    exact duplicate, not a different angle.
  - CANDIDATE_PASSER_BY_RANK's "in endgame" bonus used to add the
    exact same value a second time (a literal clone of the term just
    added above it); now a /2 fractional modifier.
  - CONNECTED_PASSERS_BY_RANK / SUPPORTED_PASSER_BY_RANK /
    OUTSIDE_PASSER_BY_DISTANCE scaled to ~1/3 magnitude: each prices a
    genuinely distinct angle on "how good is this passer" (connected
    to a partner, pawn-defended, outside the opposing majority) and
    can stack for the same pawn, so turned down rather than removed.
  - ISOLATED_DOUBLED_PAWN turned down (-11 -> -5): a per-pawn kicker
    that stacks with the whole-position DOUBLED_PAWN_PENALTY_BY_COUNT
    aggregate for the isolated+doubled subset -- different angle
    (single-worst-case flag vs. whole-position severity), not a
    duplicate, but a real overlap worth trimming.

Pieces (non-cached, real per-node cost, so these are also legibility/
perf fixes, not just magnitude):
  - Bishop: cut BISHOP_IN_CLOSED_POSITION outright -- it duplicated
    bishop mobility rather than adding a distinct angle (mobility
    already measures per-bishop diagonal blockage directly and more
    precisely than a coarse whole-board proxy).
  - Knight: killed a stale "don't block unmoved E2/D2 pawns" TODO
    (opening-book territory, not eval's job) and "a knight with an
    open file behind it is good" (dubious chess reasoning reusing an
    unrelated table -- the same lookup as the backward-pawn-blockade
    bonus, for a completely different concept).
  - Rook: killed ROOK_TRAPPING_EKING (a rook on the 7th/8th aligned
    with the enemy king is exactly the geometric pattern
    CountKingSafetyDefects' CHECK_VECTOR scan already folds into
    uPiecesPointingAtKing -- belongs in king safety, not a rook-
    specific bolt-on). Also removed pFriendRook, dead in the same
    block.
  - Queen: killed "pointing near enemy K" (QUEEN_ATTACKS_SQ_NEXT_TO_
    KING) -- computed from the queen's own mobility ray-cast, direct-
    attacks only, duplicating what _EvalKing's real (non-lazy-estimate)
    danger computation already reads from the identical attack-table
    bits a few lines away.
  - cTrapped fixed from a single COOR per color to a small [2][4] list
    (_RecordTrappedCandidate): the old single-slot design let a later
    piece's zero-mobility candidacy silently overwrite an earlier
    one's on the same side, discarding a genuinely trapped-and-
    attacked piece. This fed into search too (RecordTrappedPiece's
    move-ordering hint), not just eval scoring. RecordTrappedPiece's
    own per-ply single slot is left alone per design (would double the
    cost on the branch that already computes it, this is the
    innermost eval loop) -- now reports the MOST VALUABLE of the
    candidates found, not just whichever was found last.

King (the actual regression-and-recovery of this session):
  - Cutting the queen's "pointing near enemy K" term initially cost
    real solves (117->110 on the sd10 curated suites) despite being a
    correct duplication kill -- the general king-safety loop's
    per-square attacker accounting was piece-type-blind (a queen
    attacking a square near the king counted the same as a knight
    doing the same geometric thing), so removing the one place that
    priced queen-specific severity lost real fidelity, not just a
    duplicate. Fixed properly: added KING_QUEEN_PROXIMITY_DANGER,
    computed from bvAttacks[...].small.uQueen / .xray.uQueen bits the
    king-safety loop already reads for every one of its 11 squares --
    free (no new attack-table work) and more accurate than the killed
    term (catches x-ray/latent queen threats it never did). Calibrated
    against the killed term's own empirical magnitude (uNearKing * 8,
    capped at 6) rather than guessed. Recovered to 118/191 (a new
    session-best), now with the fidelity gap actually closed instead
    of just removed.
  - KING_SUPPORTING_OWN_PASSER_BY_RANK split out from
    SUPPORTED_PASSER_BY_RANK, which _EvalKing's "kings in front of
    passers" endgame bonus was silently reusing -- pawn-support and
    king-escort are different concepts (fires when the KING stands
    next to its own passer, not when a pawn does); scaling the shared
    table down for its real purpose was silently also scaling the
    unrelated king-escort bonus. Seeded with the table's original
    (pre-scaling) hand-tuned magnitude.
  - Collapsed three copy-pasted file-scan blocks (c-1/c/c+1, identical
    logic repeated three times) into one loop -- confirmed
    behaviorally neutral by isolated sd10 suite testing before
    landing alongside the king-safety content changes.

Net result across the three curated suites (sd10, vs. the hand-tuned+
bugfix baseline this built on): 117 -> 118, a new session best, with
every intermediate checkpoint tested via EVAL_DUMP verification +
precommit_check.sh + sd10 sweep before moving to the next change.

Deliberately deferred, written down for a future session rather than
attempted here: a holistic king-safety overhaul (the piece-type-
tropism inconsistency across knight/bishop/queen/the general
CountKingSafetyDefects scan goes deeper than tonight's scoped fixes),
recalibrating EstimatePositionalScore's iKingSwingP90 lazy-eval margin
table (the instrumentation that built it no longer exists in this
tree, and today's changes have already shifted the true swing
distribution it was calibrated against), and training a small king-
danger classifier from TWIC checkmate games (snapshot king safety
features at -10/-15 moves from real checkmates, not resignations) to
calibrate whichever of the above happens first.

Co-Authored-By: Claude Sonnet 5 <[email protected]>
Claude-Session: https://claude.ai/code/session_01M9ZDiJhiUajUxh95mTXCFJ

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