fix: initialize Carla host in main.c and add terminal error checks

Co-authored-by: aider (deepseek/deepseek-coder) <aider@aider.chat>

main.c

@@ -8,6 +8,7 @@
 #include "cli.h"
 #include "gui.h"
 #include "dispatcher.h"
+#include "carla.h"
 
 static Engine engine;
 static volatile int keep_running = 1;
@@ -87,6 +88,10 @@ int main(int argc, char *argv[]) {
         initial_state.clips[i].read_position = 0;
     }
     
+    // Initialize Carla host in the initial state (before dispatcher starts)
+    carla_init(&initial_state.carla_host, NULL);
+    carla_scan_plugins(&initial_state.carla_host);
+    
     // Initialize dispatcher
     dispatch = dispatcher_init(&initial_state);