Snapper: no question on btrfs; vendor the SysGuides scripts

- On btrfs, snapshots + zstd compression now just happen (no prompt);
  --snapper=no remains the explicit opt-out.
- Vendor scripts/snapper-*.sh + config/snapper.actions from
  SysGuides/sysguides-snapper-fedora (MIT, upstream 0a28eb4) into
  vendor/snapper/ and install from there — no runtime clone of an
  external repo, and no dependency on exec bits (fixes the
  './install.sh: Permission denied' failure seen on the test VM).
- grub-btrfs still cloned at runtime from Antynea/grub-btrfs with the
  Fedora config applied; everything else is local now.

vendor/snapper/scripts/snapper-gui-pkg.sh

@@ -0,0 +1,49 @@
+#!/usr/bin/env bash
+
+# snapper-gui-pkg.sh
+# ------------------
+# Captures the first package involved in a GUI-based transaction.
+#
+# This script:
+# - Runs during DNF5 transaction events (pre_transaction hooks)
+# - Detects if the transaction originated from a GUI
+# - Records the first package name and action (install/remove)
+#
+# This allows snapshots to have meaningful descriptions like:
+#   "GUI install firefox"
+#
+# Only the first package is recorded to keep descriptions concise.
+#
+# Project: sysguides-snapper-fedora
+# Author: Madhu Desai (SysGuides)
+# Website: https://sysguides.com
+# GitHub: https://github.com/SysGuides/sysguides-snapper-fedora
+
+PID="$1"
+ACTION="$2"
+NAME="$3"
+
+STATE_DIR="/run/snapper-actions"
+DESC_FILE="$STATE_DIR/snapper_desc_${PID}"
+PKG_FILE="$STATE_DIR/snapper_gui_${PID}"
+
+# Read previously stored description (set in PRE phase)
+desc=$(cat "$DESC_FILE" 2>/dev/null || echo "")
+
+# Only proceed if this is a GUI transaction
+[[ "$desc" != "GUI" ]] && exit 0
+
+# Only capture the first package to avoid overwriting
+[[ -f "$PKG_FILE" ]] && exit 0
+
+# Determine action type and store description
+case "$ACTION" in
+    I|U|D|R)
+        # Install / upgrade / downgrade / reinstall
+        echo "GUI install ${NAME}" > "$PKG_FILE"
+        ;;
+    E|O)
+        # Erase / obsolete
+        echo "GUI remove ${NAME}" > "$PKG_FILE"
+        ;;
+esac