feat: ACPI S3 suspend-to-RAM + battery status queries (18 patches)

P3-4: ACPI S3 sleep — suspend_to_ram() method reads _S3 AML,
writes PM1a_CNT with SLEEP_EN + SLP_TYPa. Gated to x86/x86_64.
Applies after shutdown hardening for correct context.

P3-6: ACPI battery — read_battery_status() queries _BST,
read_battery_info() queries _BIF. Returns capacity/voltage data.

18/18 patches. base + base-initfs build.

recipes/core/base/P4-acpi-s3-sleep.patch

@@ -0,0 +1 @@
+../../../local/patches/base/P4-acpi-s3-sleep.patch

recipes/core/base/recipe.toml

@@ -13,6 +13,7 @@ patches = [
     "P3-init-colored-output.patch",
     "P4-logd-persistent-logging.patch",
     "P4-acpi-shutdown-hardening.patch",
+    "P4-acpi-s3-sleep.patch",
     "P4-initfs-usb-drm-services.patch",
     "P4-initfs-network-services.patch",
     "P4-initfs-getty-services.patch",