feat: disconnect Bluetooth devices, flush disks on shutdown/reboot, display progress in login.elf window

kernel/src/Api/Power.hpp

@@ -13,8 +13,28 @@
 #include <ACPI/AcpiShutdown.hpp>
 #include <ACPI/AcpiSleep.hpp>
 
+#include "Syscall.hpp"
+
 namespace Montauk {
 
+    // Pending graceful power-off request, set by the desktop and consumed by
+    // login.elf. Kernel-global IPC channel (one outstanding request system-wide).
+    // `inline` so the single definition is shared across translation units.
+    inline int g_pendingPowerAction = POWER_REQ_QUERY;
+
+    // SYS_POWER_REQUEST. action == POWER_REQ_QUERY reads and clears the pending
+    // action; any other value records it as the pending action. Returns the
+    // pending action for queries, or 0 when recording one.
+    static int64_t Sys_PowerRequest(int action) {
+        if (action == POWER_REQ_QUERY) {
+            int pending = g_pendingPowerAction;
+            g_pendingPowerAction = POWER_REQ_QUERY;
+            return (int64_t)pending;
+        }
+        g_pendingPowerAction = action;
+        return 0;
+    }
+
     static void Sys_Reset() {
         if (Efi::g_ResetSystem) {
             /* Switch to kernel PML4 which has identity-mapped UEFI runtime regions */