fix: stabilize exclusive USB sample rate and volume

[rahul0x00]

Fix USB sample-rate fallback selection and continuous-rate parsing. Prevent duplicate software gain on resampled USB playback and correct signed PCM16 scaling. Add regression tests for rate ranges and gain handling.

[ajisth69]

@rahul0x00 have u verified it properly bro ?

[rahul0x00]

yep, works perfectly on my device

[Hk-178]

@ajisth69 i have kz zsn pro x with an upgraded dac cable . So i have it the permissions. I don't properly know what settings make the problem but for the when it asking for the permission to access it's dac, some cracking sound is breaking my ears
It's like a cd stuck and tryna rotate. It's annoying. I will attach what now turned on and it's kinda working. Idk if I did it right but I wanna say it to you
The update yesterday brought the issue. A version before it was okay without any issue .

Also , now there is a random increase and decrease of loudness on songs while loudness normalisation is turned on for tracks . especially bit perfect audio, connected to dac . I specifically didn't had any issues without the DAC 🤷🏻‍♂️

I will quote the usb log while given permission and without permission
"LastWave USB diagnostic
active=true wanted=true rate=48000 clockMatched=true hardwareVolume=false forceSoftwareVolume=true
started rate=48000Hz alt=1 wireBits=16 reported=48000 clockMatched=true fallback=false hardwareVolume=false maxPacket=388 interval=1 feedback=false
device=KZ Acoustics M2 vid=0x31b2 pid=0x311 uac=100 playbackIface=2 speed=full
alt=1 bits=16 container=16 rates=44100/48000/88200/96000
alt=2 bits=24 container=24 rates=44100/88200/48000/96000
findAltSetting(bits=16, rate=48000) -> alt=1 wireBits=16
setSampleRate(48000) UAC1 endpoint: OK
readSampleRate UAC1 endpoint: 48000 Hz
descriptors(347 B):
1201000200000040b23111030300010402010902490104010080310904000000
010100000a2401000147000201020c2402010102000101000000092406020101
0102000924030401010002000c24020501010002030000000a24060705010102
0200092403080203000700090401000001020000090401010101020000072401
040101000b2402010102100180bb000905840562000100000725010100000009
0401020101020000072401040101000b2402010103180180bb00090584059300
0100000725010100000009040200000102000009040201010102000007240105
010100142402010202100444ac0080bb00885801007701090504058401010000
0725010100000009040202010102000007240105010100142402010203180444
ac0088580180bb00007701090504054602010000072501010000000904030002
030000000921110100012246000705830310000107050303100001"

Without :
"LastWave USB diagnostic
active=false wanted=false rate=0 clockMatched=false hardwareVolume=false forceSoftwareVolume=true

Also when the bit perfect audio is turned on , the audio streaming is being stuck sometimes even when the internet connection is very stable
It happens with and without IEM DAC

[rahul0x00]

@Hk-178, disable the software volume, it's buggy as of now i think and if it still doesn't work, try this patch and see if it works or not
https://github.com/Clash-Projects/LastWave-Native/actions/runs/39215659660/artifacts/12170236898

[Hk-178]

@rahul0x00 thanks for your help , i will check😌

@rahul0x00 also it would be very good of an option if there was detailed description of what all the settings does
As a common person with somewhat knowledge I am unable to fully understand what these options stand for