add script for fetching updates

home-manager/modules/zsh/update_system_from_git.sh

@@ -0,0 +1,36 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+
+
+REPO_DIR="$HOME/Documents/Github/nixos-config"
+cd "$REPO_DIR" || { echo "Error: cannot change directory to $REPO_DIR" >&2; exit 1; }
+
+echo "Fetching latest changes from git..."
+if ! git fetch --all; then
+    echo "Error: git fetch failed" >&2
+    exit 2
+fi
+
+LOCAL_HASH=$(git rev-parse @)
+REMOTE_HASH=$(git rev-parse @{u})
+
+if [ "$LOCAL_HASH" = "$REMOTE_HASH" ]; then
+    echo "The repository is already up to date."
+    exit 0
+else
+    echo "Updates are available. Pulling latest changes..."
+    if ! git pull; then
+        echo "Error: git pull failed" >&2; exit 3
+    fi
+    echo "Repository updated successfully."
+fi
+
+chmod -R u+rwX "$REPO_DIR"
+
+sudo ./update-nixos.sh
+
+./update-home-manager.sh
+
+echo "System update from git completed successfully."
+