Revise device configuration logic and settings

The ALSA device scanner no longer inserts default sample rates when it cannot read them, preventing invalid frequency choices

Jack server settings now accept independent input and output devices during construction

The latency test utility was updated to handle separate input and output device parameters and display them accordingly

The help text for the latency tool documents the new usage with optional output device specification

Device lists in the configuration dialog are sorted to prefer devices supporting capture and playback, then USB devices, while refresh preserves existing selections

src/JackServerSettings.hpp

@@ -41,14 +41,15 @@ namespace pipedal
     void SetAlsaInputDevice(const std::string &d){ alsaInputDevice_ = d; }
     void SetAlsaOutputDevice(const std::string &d){ alsaOutputDevice_ = d; }
         JackServerSettings();
-		JackServerSettings(
-            const std::string alsaInputDevice,
+        JackServerSettings(
+            const std::string &alsaInputDevice,
+            const std::string &alsaOutputDevice,
             uint64_t sampleRate,
             uint32_t bufferSize,
             uint32_t numberOfBuffers)
             : valid_(true),
               alsaInputDevice_(alsaInputDevice),
-              alsaOutputDevice_(alsaInputDevice), // default same
+              alsaOutputDevice_(alsaOutputDevice),
               sampleRate_(sampleRate),
               bufferSize_(bufferSize),
               numberOfBuffers_(numberOfBuffers),