fix: continue fix page fault heap regression

kernel/src/Api/Process.hpp

@@ -8,6 +8,9 @@
 #pragma once
 #include <Sched/Scheduler.hpp>
 #include <Timekeeping/ApicTimer.hpp>
+#include <Memory/Paging.hpp>
+#include <Memory/PageFrameAllocator.hpp>
+#include <Memory/HHDM.hpp>
 
 #include "Syscall.hpp"
 #include "WinServer.hpp"
@@ -105,9 +108,34 @@ namespace Zenith {
         auto* proc = Sched::GetProcessByPid(pid);
         if (!proc) return -1;
 
-        // Clean up any windows owned by this process
+        // Clean up any windows owned by this process (unmaps pixel pages from desktop)
         WinServer::CleanupProcess(pid);
 
+        // Free I/O redirect buffers
+        if (proc->outBuf) {
+            Memory::g_pfa->Free(proc->outBuf);
+            proc->outBuf = nullptr;
+        }
+        if (proc->inBuf) {
+            Memory::g_pfa->Free(proc->inBuf);
+            proc->inBuf = nullptr;
+        }
+
+        // Free all user-space pages and page table structures
+        Memory::VMM::Paging::FreeUserHalf(proc->pml4Phys);
+
+        // Free kernel stack (safe — killed process isn't running on single-core)
+        if (proc->stackBase != 0) {
+            Memory::g_pfa->Free((void*)proc->stackBase, Sched::StackPages);
+            proc->stackBase = 0;
+        }
+
+        // Free the PML4 page
+        if (proc->pml4Phys != 0) {
+            Memory::g_pfa->Free((void*)Memory::HHDM(proc->pml4Phys));
+            proc->pml4Phys = 0;
+        }
+
         proc->state = Sched::ProcessState::Terminated;
         return 0;
     }