Fix garbled batch verify names in the C benchmark (static char buffer
was shared across calls). Use string literals per batch size instead.
Fix batch verify self-test: use sign() (safe path) instead of
sign_xonly() since the test key has odd-y pubkey.
Add batch sizes 4 and 64 to the benchmark for finer granularity.
Batch verification results (x86_64 standalone, same pubkey):
Batch µs/event events/sec vs individual
1 36.6 27,322 1.0x
4 15.2 66,007 2.4x
8 11.1 89,787 3.3x
16 9.2 109,290 4.0x
32 8.6 115,942 4.2x
64 8.3 120,960 4.4x
200 7.8 127,689 4.7x
vs Kotlin: C batch is 1.3-1.7x faster across all batch sizes.
At 200 events: 127K ev/s (C) vs 96K ev/s (Kotlin).
https://claude.ai/code/session_011KVZhDcV2G7idNWEBz12GY
Claude
3544c2cbc3