feat: add USB mass storage and DRM/KMS service files to initfs

Phase B1+B2 from BOOT-PROCESS-AUDIT:
- 45_usbscsid.service: USB mass storage driver in initfs (requires xhcid)
- 30_redox-drm.service: DRM/KMS display driver in initfs (requires hwd+pcid-spawner)
Both condition-architecture-gated to x86/x86_64.

local/patches/base/P4-initfs-usb-drm-services.patch

@@ -0,0 +1,22 @@
+--- /dev/null
++++ b/init.initfs.d/45_usbscsid.service
+@@ -0,0 +1,8 @@
++[unit]
++description = "USB Mass Storage Driver"
++requires_weak = ["40_drivers.target"]
++condition_architecture = ["x86", "x86_64"]
++
++[service]
++cmd = "usbscsid"
++type = "notify"
+--- /dev/null
++++ b/init.initfs.d/30_redox-drm.service
+@@ -0,0 +1,8 @@
++[unit]
++description = "DRM/KMS Display Driver"
++requires_weak = ["20_graphics.target", "40_hwd.service", "40_pcid-spawner-initfs.service"]
++condition_architecture = ["x86", "x86_64"]
++
++[service]
++cmd = "redox-drm"
++type = "notify"

recipes/core/base/P4-initfs-usb-drm-services.patch

@@ -0,0 +1 @@
+../../../local/patches/base/P4-initfs-usb-drm-services.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-initfs-usb-drm-services.patch",
 ]
 
 [build]