- 15 FX blocks implemented with per-block state isolation
- All blocks <500us per 256-sample block (reverb closest at 465us on x86)
- 57 unit tests all passing (per-effect, chain, bypass, state isolation)
- Benchmark script at scripts/benchmark_fx.py
- Vectorised delay reads via read_block_varying()
- scipy.lfilter for EQ (3-band RBJ) and reverb damping
- Fixed _DelayLine.write_block wraparound crash for large blocks
- Comb/Allpass buffers sized to BLOCK_SIZE * 2 minimum
