Phase A NNUE: feature-indexing spec, annotation/training pipeline, dump nnuefeatures

Builds out the NNUE Phase A prototype per docs/NNUE.md:

- src/nnuefeatures.c: standalone HalfKAv2_hm feature-index reference
  implementation (new `dump nnuefeatures` command), sourced from
  Stockfish's half_ka_v2_hm.{h,cpp} (sf_16 tag), including the 0x88->64
  square conversion typhoon's own board representation needs.
- annotate_pgns/: sharded TWIC/self-play annotation harness
  (annotate.py), position extraction, quiet-position filtering (flat
  and game-shaped, plus an upstream --prefilter-quiet option),
  train/holdout game-level stratified split, WDL-sigmoid K fitting,
  the Python HalfKAv2_hm reference encoder (nnue_feature_spec.py) and
  its bit-for-bit cross-checker against the C side
  (cross_check_features.py), and a first PyTorch training pipeline
  (nnue_model.py, nnue_train.py, build_training_tensors.py) -- a
  256x2-32-32-1-ish net trained locally on CPU against ~1.85M quiet
  TWIC positions as a pipeline/framework validation pass.
- Finish an in-progress InitMagic/InitLMRTable/InitEval ->
  InitializeBitboardMagic/InitializeLMRTable/InitializeEval rename:
  chess.h's prototypes hadn't been updated to match the already-renamed
  definitions/call sites, leaving 4 implicit-function-declaration
  warnings.
- tests/arasan.epd: new curated EPD suite.
- docs/: add the project's design docs (previously untracked).

Co-Authored-By: Claude Sonnet 5 <[email protected]>

1 files changed, 6 insertions, 3 deletions

diff --git a/src/chess.h b/src/chess.h
index 3a1f842..05928a3 100755
--- a/src/chess.h
+++ b/src/chess.h
@@ -3319,7 +3319,7 @@ void
 InitializePawnAttackOriginTable(void);
 
 void
-InitMagic(void);
+InitializeBitboardMagic(void);
 
 #ifdef DEBUG
 ULONG CheckVectorWithIndex(int i, ULONG uColor);
@@ -3774,7 +3774,7 @@ ThreadUnderTerminatingSplit(SEARCHER_THREAD_CONTEXT *);
 extern SCORE g_iLMRQuietReduction[MAX_PLY_PER_SEARCH + 1][LMR_TABLE_MAX_MOVES + 1];
 
 void
-InitLMRTable(void);
+InitializeLMRTable(void);
 
 FLAG
 CanWeReduceOrPruneMove(IN SEARCHER_THREAD_CONTEXT *ctx,
@@ -4255,11 +4255,14 @@ WriteEvalDNA(char *szFilename);
 FLAG
 ImportEvalDNA(char *p);
 
+void
+DumpNnueFeatures(POSITION *pos);
+
 FLAG
 ReadEvalDNA(char *szFilename);
 
 void
-InitEval();
+InitializeEval();
 
 SCORE
 Eval(SEARCHER_THREAD_CONTEXT *, SCORE, SCORE, SCORE (*)[2]);