feat(kernel): NT-inspired Object Manager, dispatcher and IRQL

Take inspiration from the Windows NT Executive and add its most iconic
subsystem to SUB-OS: a typed, reference-counted object namespace.

- kernel/nt/ob.c + include/kernel/nt/ob.h (new):
  * Object Manager (Ob): typed objects (Directory/Event/Semaphore/Mutant) in a
    hierarchical named namespace rooted at "\", with NT-style deletion once
    handle_count and ref_count both reach zero (unless permanent).
  * Handle table (Io/Ob): NT-shaped non-zero 4-aligned HANDLEs into a 256-slot
    system table; open/reference/close with proper refcount transfer.
  * Dispatcher (Ke): set/reset/test events (auto- and manual-reset) and
    release/wait semaphores, poll-style.
  * Software IRQL: PASSIVE/APC/DISPATCH/HIGH with raise/lower semantics.
  * NTSTATUS result codes and NT_SUCCESS().
  * ob_init() seeds the standard namespace (\BaseNamedObjects, \Device,
    \ObjectTypes, \KernelObjects) plus a boot event and an I/O semaphore.
- Wired ob_init() into the [12/14] boot step; added kernel/nt/ob.c to CORE_SRCS.
- LazyBox: `objdir [\path]` walks the object namespace tree (WinObj-style);
  `ntobj` prints Ob statistics and runs a live dispatcher/handle/IRQL demo.

Verified live in the GUI terminal (screenshotted): 7 seeded objects
(5 directories, 1 event, 1 semaphore), auto-reset event signalling, handle
close reclaiming the object, and PASSIVE->DISPATCH->PASSIVE IRQL transitions.
Clean build on x86_64/aarch64/armv8i; 0 panics / 0 OOM.

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

include/kernel/nt/ob.h

@@ -0,0 +1,105 @@
+#ifndef _KERNEL_NT_OB_H
+#define _KERNEL_NT_OB_H
+
+// -----------------------------------------------------------------------------
+// SUB-OS NT-Inspired Object Manager
+//
+// A faithful-in-spirit port of the Windows NT Executive Object Manager (Ob):
+// every kernel resource is a typed, reference-counted object living in a
+// hierarchical named namespace ("\BaseNamedObjects\MyEvent"), reached through a
+// per-process handle table. Also carries NT dispatcher primitives (events,
+// semaphores, mutants) and a software IRQL model.
+// -----------------------------------------------------------------------------
+
+#include <stdint.h>
+#include <stdbool.h>
+#include <stddef.h>
+
+// NTSTATUS-style result codes (high bit set == error, as in NT).
+typedef int32_t NTSTATUS;
+#define STATUS_SUCCESS            ((NTSTATUS)0x00000000)
+#define STATUS_UNSUCCESSFUL       ((NTSTATUS)0xC0000001)
+#define STATUS_INVALID_HANDLE     ((NTSTATUS)0xC0000008)
+#define STATUS_INSUFFICIENT_RES   ((NTSTATUS)0xC000009A)
+#define STATUS_OBJECT_NAME_EXISTS ((NTSTATUS)0xC0000035)
+#define STATUS_OBJECT_NOT_FOUND   ((NTSTATUS)0xC0000225)
+#define NT_SUCCESS(s)             (((NTSTATUS)(s)) >= 0)
+
+typedef enum {
+    OB_TYPE_DIRECTORY = 0,
+    OB_TYPE_EVENT,
+    OB_TYPE_SEMAPHORE,
+    OB_TYPE_MUTANT,
+    OB_TYPE_MAX
+} ob_type_t;
+
+#define OB_NAME_MAX   48
+#define OB_DIR_MAX    32   // children per directory
+#define OB_HANDLE_MAX 256  // system handle table size
+
+typedef struct ob_object ob_object_t;
+
+struct ob_object {
+    ob_type_t    type;
+    char         name[OB_NAME_MAX];
+    int32_t      ref_count;     // outstanding pointer references
+    int32_t      handle_count;  // outstanding open handles
+    bool         permanent;     // survives handle_count/ref_count reaching 0
+    ob_object_t* parent;        // containing directory (NULL for the root)
+
+    union {
+        struct { ob_object_t* children[OB_DIR_MAX]; int count; } dir;
+        struct { bool signaled; bool manual_reset; }             event;
+        struct { int32_t count; int32_t limit; }                 sem;
+        struct { bool held; uint32_t owner; int32_t recursion; } mutant;
+    } body;
+};
+
+// A HANDLE indexes the system handle table; -1 is the invalid handle.
+typedef int32_t HANDLE;
+#define OB_INVALID_HANDLE ((HANDLE)-1)
+
+// Lifecycle -------------------------------------------------------------------
+void         ob_init(void);
+const char*  ob_type_name(ob_type_t t);
+ob_object_t* ob_root_directory(void);
+
+NTSTATUS     ob_create_object(ob_type_t type, const char* name,
+                              ob_object_t* dir, ob_object_t** out);
+ob_object_t* ob_lookup_path(const char* path);   // "\BaseNamedObjects\Name"
+void         ob_reference_object(ob_object_t* obj);
+void         ob_dereference_object(ob_object_t* obj);
+void         ob_make_permanent(ob_object_t* obj);
+
+// Handle table ----------------------------------------------------------------
+HANDLE       ob_open_handle(ob_object_t* obj);
+ob_object_t* ob_reference_by_handle(HANDLE h);
+NTSTATUS     ob_close_handle(HANDLE h);
+int          ob_open_handle_count(void);
+
+// Dispatcher primitives (non-blocking, poll-style) ----------------------------
+NTSTATUS ke_set_event(ob_object_t* evt);
+NTSTATUS ke_reset_event(ob_object_t* evt);
+bool     ke_test_event(ob_object_t* evt);            // true if signaled (auto-reset consumes)
+NTSTATUS ke_release_semaphore(ob_object_t* sem, int32_t count);
+bool     ke_wait_semaphore(ob_object_t* sem);        // true if a unit was acquired
+
+// Enumeration (for the objdir tool) -------------------------------------------
+int          ob_dir_child_count(ob_object_t* dir);
+ob_object_t* ob_dir_child(ob_object_t* dir, int index);
+void         ob_get_stats(uint32_t* out_objects, uint32_t* out_handles,
+                          uint32_t per_type[OB_TYPE_MAX]);
+
+// Software IRQL model ---------------------------------------------------------
+typedef enum {
+    PASSIVE_LEVEL  = 0,
+    APC_LEVEL      = 1,
+    DISPATCH_LEVEL = 2,
+    HIGH_LEVEL     = 15
+} KIRQL;
+
+KIRQL ke_get_current_irql(void);
+KIRQL ke_raise_irql(KIRQL new_irql);   // returns previous IRQL
+void  ke_lower_irql(KIRQL old_irql);
+
+#endif // _KERNEL_NT_OB_H