Fixes to Changes.

Added helper functions to combine and intersect ALSA device capabilities, ensuring validation works across separate input and output devices

Updated buffer handling logic to use both selected devices and compute min/max sizes appropriately

Revised validation to check both ALSA input and output devices when enabling the OK button

Simplified rendering logic to intersect sample rates and buffer options for the chosen devices

AlsaDriver single device err calls fixed.

Added guidance on using USB audio interfaces or Raspberry Pi audio HATs and choosing separate ALSA input and output devices during setup

Clarified that the Audio Device Settings dialog allows independent configuration of input and output devices, with updated instructions for selecting audio channels

src/AlsaDriver.cpp

@@ -1955,8 +1955,8 @@ namespace pipedal
             }
             if (err < 0)
             {
-                throw PiPedalStateException(SS(alsaDeviceName << " playback device not found. "
-                                                              << "(" << snd_strerror(err) << ")"));
+                throw PiPedalStateException(SS(outDev << " playback device not found. "
+                                                             << "(" << snd_strerror(err) << ")"));
             }
 
             for (int retry = 0; retry < 15; ++retry)
@@ -1970,7 +1970,7 @@ namespace pipedal
                 break;
             }
             if (err < 0)
-                throw PiPedalStateException(SS(alsaDeviceName << " capture device not found."));
+                throw PiPedalStateException(SS(inDev << " capture device not found."));
 
             if (snd_pcm_hw_params_malloc(&playbackHwParams) < 0)
             {