feat: implement capability-based memory management foundation

kernel/src/cap/object.rs

@@ -0,0 +1,29 @@
+use crate::mem::address::PhysAddr;
+use core::sync::atomic::{AtomicUsize, Ordering};
+
+#[derive(Debug)]
+pub enum ObjectType {
+    Untyped,     
+    Frame,       
+    CNode,       
+    ThreadBlock, 
+    PageTable,   
+}
+
+pub struct KernelObject {
+    pub phys_addr: PhysAddr,
+    pub size_bits: u8,
+    pub obj_type: ObjectType,
+    pub ref_count: AtomicUsize,
+    pub owner_id: u64,
+}
+
+impl KernelObject {
+    pub fn add_ref(&self) {
+        self.ref_count.fetch_add(1, Ordering::Relaxed);
+    }
+
+    pub fn release(&self) -> bool {
+        self.ref_count.fetch_sub(1, Ordering::Release) == 1
+    }
+}