- Untrack all .o and .a files under third_party/ (rnnoise, libspecbleach)
- Add third_party/**/*.o and third_party/**/*.a to .gitignore
- Fix FFTW configure cross-compilation: add $(strip ...) around fftw_host
macro call and explicit --build flag so configure detects cross-compile
correctly (GNU make backslash-continuation in define blocks inserts a
leading space, causing --host= arm-... to be parsed as empty --host)
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
