Feature: Add command execution on child processes feature

Temporary: Add configuration sample for forward compatibility

src/command.h

@@ -0,0 +1,24 @@
+#ifndef COMMAND_H
+#define COMMAND_H
+
+#include "string.h"
+
+typedef struct Arena Arena;
+typedef struct Discovery Discovery;
+typedef struct Configuration Configuration;
+
+struct Command
+{
+  Arena* a;
+  StringView app;
+  const char** args;
+};
+
+typedef struct Argument Argument;
+typedef struct Command Command;
+
+Command command_create(Arena* a, Discovery* d, Configuration* c);
+
+int command_run(Command* cmd);
+
+#endif