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-desc.sh

@@ -0,0 +1,35 @@
+#!/usr/bin/env bash
+
+# snapper-desc.sh
+# ----------------
+# Determines a human-readable description for the transaction.
+#
+# This script inspects the process that triggered the DNF5 transaction.
+#
+# Behavior:
+# - If the transaction originates from GUI tools (PackageKit / dnf5daemon),
+#   it returns "GUI"
+# - Otherwise, it returns the actual command (e.g., "dnf install vim")
+#
+# This description is later used by Snapper for snapshot naming.
+#
+# Project: sysguides-snapper-fedora
+# Author: Madhu Desai (SysGuides)
+# Website: https://sysguides.com
+# GitHub: https://github.com/SysGuides/sysguides-snapper-fedora
+
+PID="$1"
+
+# Get the full command of the originating process
+cmd=$(ps -o command --no-headers -p "$PID" 2>/dev/null || echo "Unknown Task")
+
+case "$cmd" in
+    */dnf5daemon* | */packagekitd*)
+        # GUI-based transaction
+        echo "GUI"
+        ;;
+    *)
+        # CLI or unknown source
+        echo "$cmd"
+        ;;
+esac