ptos: ps: Add thread management groundwork

Signed-off-by: Chloe M <chloe@mensia.org>

service/ptos/ps/thread.c

@@ -0,0 +1,39 @@
+/*
+ * Copyright (c) 2026, Chloe M.
+ * Provided under the BSD-3 clause.
+ *
+ * Description: Thread management
+ * Author:      Chloe M.
+ */
+
+#include <ps/thread.h>
+#include <ps/process.h>
+#include <ex/pool.h>
+#include <atomic.h>
+
+/* Globals */
+static UQUAD NextThreadTid = 0;
+
+PT_STATUS
+PsCreateThread(struct _PROCESS *Parent, ULONG Flags, THREAD **Result)
+{
+    THREAD *Thread;
+
+    if (Parent == NULL || Result == NULL) {
+        return STATUS_INVALID_PARAM;
+    }
+
+    Thread = ExAllocatePoolWithTag(
+        POOL_NON_PAGED,
+        sizeof(*Thread),
+        THREAD_POOL_TAG
+    );
+
+    if (Thread == NULL) {
+        return STATUS_NO_MEMORY;
+    }
+
+    Thread->Tid = AtomicIncQuad(&NextThreadTid);
+    *Result = Thread;
+    return STATUS_SUCCESS;
+}