Initial scaffold: idempotent Sunshine + Moonlight installer for Omarchy

Sets up bidirectional game streaming across Omarchy/Hyprland/Wayland
machines (NVIDIA desktop and AMD Framework laptop), with the Macbook
as an additional Moonlight client.

The same install.sh runs on either machine; GPU vendor is detected at
runtime and the appropriate hardware-encode packages are installed.

Includes:
- KMS capture setup (cap_sys_admin on sunshine, input group, uinput udev rule)
- ufw / firewalld port opening when a firewall is active
- systemd --user service + loginctl enable-linger for always-on hosting
- uninstall.sh with --purge for user data removal
- Flags to install host-only or client-only

lib/packages.sh

@@ -0,0 +1,35 @@
+#!/usr/bin/env bash
+# Install Sunshine, Moonlight, and GPU-specific hardware-encode dependencies.
+
+# Default to source build (canonical AUR package). Override with SUNSHINE_PKG=sunshine-bin
+# in the environment for the precompiled build (much faster install).
+: "${SUNSHINE_PKG:=sunshine}"
+
+install_sunshine() {
+  yay_install "$SUNSHINE_PKG"
+}
+
+install_moonlight() {
+  # moonlight-qt is in the AUR (also a -bin variant). yay handles both.
+  yay_install moonlight-qt
+}
+
+install_gpu_encoder_packages() {
+  case "$GPU_VENDOR" in
+    nvidia)
+      # NVENC works through the proprietary driver. libva-nvidia-driver lets some
+      # apps use VAAPI on NVIDIA; not strictly required for Sunshine NVENC but useful.
+      yay_install nvidia-utils libva-nvidia-driver
+      ;;
+    amd)
+      # VAAPI (mesa) + Vulkan for AMD hardware encode paths.
+      yay_install libva-mesa-driver mesa-vdpau vulkan-radeon
+      ;;
+    intel)
+      yay_install intel-media-driver vulkan-intel
+      ;;
+    *)
+      info "Unknown GPU vendor; skipping vendor-specific encoder packages."
+      ;;
+  esac
+}