feat(kernel,gui): NT Configuration Registry + GUI Object Browser

Kernel (NT Configuration Manager):
- kernel/nt/reg.c + include/kernel/nt/reg.h (new): a hive/key/value registry
  rooted at "\Registry", with typed values (REG_SZ/DWORD/QWORD/BINARY/MULTI_SZ,
  type codes matching Win32). reg_create_key/reg_open_key walk backslash paths;
  setters/getters, enumeration, and value->string rendering. reg_init() seeds
  \Registry\Machine (Hardware, System\CurrentControlSet\Control, Software\SUB-OS)
  and \Registry\User\.DEFAULT. Wired into the [12/14] boot step.
- LazyBox `reg query|add|set|stats` explores and edits the registry.

GUI:
- gui/gui_apps.c: "Object Browser" -- a WinObj-style live tree view of the NT
  object namespace (\), flattening directories/events/semaphores/mutants with
  indentation, per-type colouring, ref/handle counts, live object/handle stats,
  and click-to-scroll. Registered in the app table (start menu).

Verified live in the GUI terminal (screenshotted): registry reports 13 keys /
11 values; `reg query \Registry\Machine\Software\SUB-OS` lists Version,
BuildArch (REG_SZ), GrowableHeap/ObjectManager (REG_DWORD) and InstallCookie
(REG_QWORD) with correct types. Clean build on x86_64/aarch64/armv8i; 0 panics.

Co-Authored-By: Claude Opus 4.8 <[email protected]>
Claude-Session: https://claude.ai/code/session_01Fh5z6V7nGPbHvqVG5p4CXX

kernel/main.c

@@ -8,6 +8,7 @@
 #include <kernel/workqueue.h>
 #include <kernel/module.h>
 #include <kernel/nt/ob.h>
+#include <kernel/nt/reg.h>
 #include <kernel/trace.h>
 #include <kernel/namespace.h>
 #include <kernel/syslog.h>
@@ -241,6 +242,7 @@ static void subos_modular_core_boot(void) {
     metrics_init();
     cron_init();
     ob_init();
+    reg_init();
     service_manager_init();
     printk(ANSI_BRIGHT_GREEN "OK\n" ANSI_RESET);