feat: establish the bounded production architecture

include/app_interfaces.h

@@ -0,0 +1,10 @@
+#pragma once
+
+#include <stdbool.h>
+#include <stddef.h>
+#include <stdint.h>
+
+typedef struct { uint64_t (*now_ms)(void *context); void *context; } clock_t;
+typedef struct { uint32_t (*next_u32)(void *context); void *context; } random_source_t;
+typedef struct { bool (*schedule_after_ms)(void *context, uint32_t delay_ms); void *context; } scheduler_t;
+typedef struct { bool (*send)(void *context, int client_id, const char *data, size_t length); void *context; } transport_t;