feat: add build numbering

kernel/src/Api/BuildNo.hpp

@@ -0,0 +1,15 @@
+/*
+    * BuildNo.hpp
+    * Monotonic kernel build number.
+    *
+    * This file is the source of truth for the build number. It is regenerated
+    * (incremented) by scripts/bump-build.sh whenever the kernel or userspace
+    * sources change, via a rule in kernel/GNUmakefile. Do not edit the number
+    * by hand; the build system manages it.
+    *
+    * Copyright (c) 2026 Daniel Hammer
+*/
+
+#pragma once
+
+#define MONTAUK_BUILD_NUMBER 1

kernel/src/Api/Info.hpp

@@ -7,6 +7,7 @@
 #pragma once
 #include <Sched/Scheduler.hpp>
 
+#include "BuildNo.hpp"
 #include "Syscall.hpp"
 
 namespace Montauk {
@@ -22,7 +23,8 @@ namespace Montauk {
         for (int i = 0; ver[i]; i++) outInfo->osVersion[i] = ver[i];
         outInfo->osVersion[5] = '\0';
 
-        outInfo->apiVersion = 3;
+        outInfo->apiVersion = 4;
         outInfo->maxProcesses = Sched::MaxProcesses;
+        outInfo->buildNumber = MONTAUK_BUILD_NUMBER;
     }
 };

kernel/src/Api/Syscall.hpp

@@ -282,6 +282,7 @@ namespace Montauk {
         char osVersion[32];
         uint32_t    apiVersion;
         uint32_t    maxProcesses;
+        uint32_t    buildNumber;   // monotonic kernel build number (see BuildNo.hpp)
     };
 
     struct NetCfg {