0e77adb4c3
- Full FFT overlap-add IR convolution in IRLoader (process(), set_mix(), toggle) - Lazy FFT computation — IR FFT padded to correct block+ir size on first process() - Wet/dry mix control, enabled/disabled toggle with tail clearing - Fixed pipeline._apply_ir_cab() to delegate to IRLoader.process() instead of poking internals (old code had array-size mismatch bug: IR FFT at ir_len vs block FFT at conv_size) - 46 tests: loading, convolution correctness, overlap-add state, mix, toggle, directory listing, performance budget (all <5ms even at 8192 taps), edge cases - scripts/download_irs.sh: free IR pack downloader (God's Cab, Seacow)