- audio_compressor.h/c moved to lib/ (alongside opus_codec, mem, debug_config)
- lib/Makefile.am: added to libuasync_a_SOURCES
- utun_sources.cmake: removed from _cfg_src (GLOB from lib/ picks it up)
- tests/Makefile.am: test_audio_compressor added to check_PROGRAMS
- test includes simplified (debug_config.h, mem.h — lib/ in include path)