refactor: The session sync and kernel headers scripts in patches/

patches/README.md

@@ -7,5 +7,7 @@ read and reviewed on their own. `lib/*.sh` reads them with `patch_file
 | File | Used by | What |
 |---|---|---|
 | `steamify-fremont-poweroff.c` | `lib/fremont-poweroff.sh` (Steam Machine support) | Kernel module (DKMS): clears GPIO 18's S4/S5 wake bit before power-off, so the Steam Machine stays off with recent kernels |
+| `sync-steamos-session.sh` | `lib/login-manager.sh` (SteamOS conversion, plasma-login-manager) | The sync bridge: copies Steam's session choice from `zz-steamos-autologin.conf` into `plasmalogin.conf`'s `[Autologin]` |
+| `ensure-kernel-headers.sh` | `lib/steam-machine.sh` (Steam Machine support) | Run at boot: installs missing headers for every installed kernel |
 | `steamify-notifier.py` | `lib/update-notifier.sh` (Update notifications) | The daily check: notification and tray icon when there's a new release |
 | `cros-ec-cec-single-port.patch` | `lib/cec.sh` (HDMI-CEC) | Makes Valve's Steam Machine CEC driver find amdgpu's HDMI port |

patches/ensure-kernel-headers.sh

@@ -0,0 +1,14 @@
+#!/bin/bash
+# Installed by cachyos-gamescope-boot: install missing -headers for every
+# installed kernel, so DKMS builds leds-valve for it.
+set -u
+missing=()
+for k in $(pacman -Qqo /usr/lib/modules/*/pkgbase 2>/dev/null | sort -u); do
+    pacman -Q "${k}-headers" >/dev/null 2>&1 && continue
+    pacman -Si "${k}-headers" >/dev/null 2>&1 && missing+=("${k}-headers")
+done
+[[ ${#missing[@]} -eq 0 ]] && exit 0
+# Another pacman is running (e.g. an update): try again next boot.
+[[ -e /var/lib/pacman/db.lck ]] && { echo "pacman is busy, skipping"; exit 0; }
+echo "Installing missing kernel headers: ${missing[*]}"
+exec pacman -S --needed --noconfirm "${missing[@]}"

patches/sync-steamos-session.sh

@@ -0,0 +1,16 @@
+#!/bin/bash
+SRC="/etc/plasmalogin.conf.d/zz-steamos-autologin.conf"
+DEST="/etc/plasmalogin.conf"
+
+[[ -f "$SRC" ]] || exit 0
+SESSION=$(grep -oP '^Session=\K.*' "$SRC")
+[[ -z "$SESSION" ]] && exit 0
+
+# Only touch Session= inside [Autologin]; other sections may have their own.
+if sed -n '/^\[Autologin\]/,/^\[/p' "$DEST" | grep -q '^Session='; then
+    sed -i "/^\[Autologin\]/,/^\[/ s|^Session=.*|Session=$SESSION|" "$DEST"
+elif grep -q '^\[Autologin\]' "$DEST"; then
+    sed -i "/^\[Autologin\]/a Session=$SESSION" "$DEST"
+else
+    printf '\n[Autologin]\nSession=%s\n' "$SESSION" >> "$DEST"
+fi