Add missing includes and link dependencies for GCC 16

GCC 16 on Arch Linux no longer implicitly includes certain standard
headers. This causes 'not declared' errors for POSIX functions.

- PiPedalCommon/src/CMakeLists.txt: Link asound library for ALSA sequencer
- DBusDispatcher.cpp: Add <unistd.h> for read()/write()/close()
- AuxInTest.cpp: Add <unistd.h> for sleep()
- kconfigMain.cpp: Add <unistd.h> for getuid()
- ModFileTypes.cpp: Add <mutex> for std::mutex/std::lock_guard

src/kconfigMain.cpp

@@ -55,6 +55,7 @@
 #include <atomic>
 #include "BootConfig.hpp"
 #include <array>
+#include <unistd.h>
 #include "CommandLineParser.hpp"
 #include "PrettyPrinter.hpp"
 #include "SysExec.hpp"