feat: add cwd tracking to kernel, remove shell hack, update system utilities to use getcwd, fix tcc libc stub, fix nonexistent directory issue

kernel/src/Sched/Scheduler.cpp

@@ -91,6 +91,7 @@ namespace Sched {
             processTable[i].heapNext = 0;
             processTable[i].args[0] = '\0';
             processTable[i].user[0] = '\0';
+            processTable[i].cwd[0] = '\0';
             processTable[i].runningOnCpu = -1;
             processTable[i].killPending = false;
             processTable[i].waitingForPid = -1;
@@ -301,6 +302,23 @@ namespace Sched {
             }
         }
 
+        {
+            auto* cpu = Smp::GetCurrentCpuData();
+            int parentSlot = cpu->currentSlot;
+            if (parentSlot >= 0 && processTable[parentSlot].cwd[0]) {
+                int i = 0;
+                for (; i < 255 && processTable[parentSlot].cwd[i]; i++) {
+                    proc.cwd[i] = processTable[parentSlot].cwd[i];
+                }
+                proc.cwd[i] = '\0';
+            } else {
+                proc.cwd[0] = '0';
+                proc.cwd[1] = ':';
+                proc.cwd[2] = '/';
+                proc.cwd[3] = '\0';
+            }
+        }
+
         proc.redirected = false;
         proc.parentPid = -1;
         proc.outBuf = nullptr;

kernel/src/Sched/Scheduler.hpp

@@ -44,6 +44,7 @@ namespace Sched {
         uint64_t heapNext;        // Simple bump allocator for user heap
         char args[256];           // Command-line arguments (set by parent via Spawn)
         char user[32];            // Owner user name (inherited from parent on spawn)
+        char cwd[256];            // Absolute current working directory
 
         int runningOnCpu;         // CPU index running this process (-1 if not running)
         bool killPending = false; // Set by Sys_Kill when target is running on another CPU