Optimize installer: preflight checks, tuned conf, doctor, faster default

Layers a few things on top of the initial scaffold:

- Default to sunshine-bin (precompiled, ~seconds) instead of building from
  source. --from-source restores the old behavior.
- Add lib/preflight.sh: catches the gotchas before any work is done —
  Wayland session, NVIDIA driver responsive, nvidia-drm.modeset, amdgpu
  loaded, pipewire-pulse present, SSH-without-session warning.
- Add lib/config.sh: writes a tuned ~/.config/sunshine/sunshine.conf with
  per-vendor encoder settings (NVENC P1+ll+cbr, VAAPI ultralowlatency,
  QuickSync veryfast), KMS capture, pulse audio sink. Uses a
  "# managed-by: omarchy-moonlight" marker; removing it hands ownership
  back to the user and the installer won't touch the file again.
- Add lib/verify.sh: post-install verification of every step
  (cap_sys_admin set, group resolves, udev rule present, /dev/uinput
  exists, encoder reachable, service active, :47990 listening). Same
  checks are reachable standalone via --doctor.
- Install runtime helpers (pipewire-pulse, vulkan-tools, libva-utils)
  alongside Sunshine for diagnostics + audio.
- Uninstall handles both sunshine + sunshine-bin and the -bin moonlight
  variant.
- README documents the tuning table, the new flags, and the modeset
  troubleshooting path.

uninstall.sh

@@ -38,13 +38,17 @@ if loginctl show-user "$USER" -p Linger --value 2>/dev/null | grep -qx yes; then
 fi
 
 step "Removing packages"
-if pacman -Qi sunshine >/dev/null 2>&1; then
-  as_root pacman -Rns --noconfirm sunshine
-elif pacman -Qi sunshine-bin >/dev/null 2>&1; then
-  as_root pacman -Rns --noconfirm sunshine-bin
-fi
-if [[ $KEEP_MOONLIGHT -eq 0 ]] && pacman -Qi moonlight-qt >/dev/null 2>&1; then
-  as_root pacman -Rns --noconfirm moonlight-qt
+for pkg in sunshine sunshine-bin; do
+  if pacman -Qi "$pkg" >/dev/null 2>&1; then
+    as_root pacman -Rns --noconfirm "$pkg"
+  fi
+done
+if [[ $KEEP_MOONLIGHT -eq 0 ]]; then
+  for pkg in moonlight-qt moonlight-qt-bin; do
+    if pacman -Qi "$pkg" >/dev/null 2>&1; then
+      as_root pacman -Rns --noconfirm "$pkg"
+    fi
+  done
 fi
 
 step "Removing udev rule (if we wrote one)"