Update NNUE architecture to SFNNv18 and net nn-c9e480e92425.nnue
Introduce the SFNNv18 NNUE architecture:
- Replace HalfKAv2_hm with K32Q2 feature set, conditioning on own king position (32 buckets) and opponent queen presence (2 states).
- Expand layer stacks from 8 to 32, indexed by piece count and queen bucket (pc_bucket * 4 + queen_bucket).
- Quantize feature transformer weights to int8 and simplify parameter serialization to uncompressed little-endian format, removing LEB128 routines.
- Update accumulator management and Finny table caches to track opponent queen presence, requiring accumulator refresh on king moves and opponent queen captures or promotions.
- Update default net to nn-c9e480e92425.nnue.
Passed STC: https://tests.stockfishchess.org/tests/view/6ac90b275349156614d9415f
```
LLR: 2.94 (-2.94,2.94) <0.00,2.00>
Total: 23808 W: 6198 L: 5910 D: 11700
Ptnml(0-2): 27, 2674, 6237, 2916, 50
```
Passed rebased LTC: https://tests.stockfishchess.org/tests/view/6ac9e0a15349156614d9425b
```
LLR: 2.97 (-2.94,2.94) <0.50,2.50>
Total: 28680 W: 7533 L: 7236 D: 13911
Ptnml(0-2): 7, 2913, 8203, 3210, 7
```
nodestime STC: https://tests.stockfishchess.org/tests/view/6acae0855349156614d943a8
```
LLR: 2.95 (-2.94,2.94) <0.50,2.50>
Total: 20032 W: 5518 L: 5200 D: 9314
Ptnml(0-2): 110, 2208, 5086, 2478, 134
```
nodestime LTC: https://tests.stockfishchess.org/tests/view/6acaeece5349156614d943b1
```
LLR: 2.95 (-2.94,2.94) <0.50,2.50>
Total: 16386 W: 4450 L: 4183 D: 7753
Ptnml(0-2): 6, 1564, 4785, 1833, 5
```
Ablations (STC):
https://tests.stockfishchess.org/tests/view/6acc23a320d2b3b562a7e927
https://tests.stockfishchess.org/tests/view/6acc23c220d2b3b562a7e929
https://tests.stockfishchess.org/tests/view/6acc23e120d2b3b562a7e92b
https://tests.stockfishchess.org/tests/view/6acd7b39733e627f7058beac
Verification Run (STC) for PR commit:
https://tests.stockfishchess.org/tests/view/6ace1595733e627f7058bf74
All three single addition ablations failed non-reg SPRT against branch. The closest one seems to be output buckets only, which might have been a gainer on it's own.
closes https://github.com/official-stockfish/Stockfish/pull/7215
Bench: 1559611