Fix shutdown command by using full path to /sbin/shutdown

Updated shutdown and reboot commands to use absolute paths to ensure
they work correctly with the sudoers configuration. Also updated the
sudoers file to allow shutdown with specific arguments.

Changes:
- Use /sbin/shutdown instead of just shutdown
- Use /sbin/reboot instead of just reboot
- Updated sudoers to allow both 'shutdown -h +1' and 'shutdown -h now'
- Ensures commands match sudoers whitelist exactly

The restart was working because reboot might be in PATH, but shutdown
needs the full path to match the sudoers entry.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

wedding-phone-shutdown

@@ -4,5 +4,6 @@
 # Then: sudo chmod 0440 /etc/sudoers.d/wedding-phone-shutdown
 
 # Allow user to run shutdown and reboot commands without password
-berwn ALL=(ALL) NOPASSWD: /sbin/shutdown
+berwn ALL=(ALL) NOPASSWD: /sbin/shutdown -h +1
+berwn ALL=(ALL) NOPASSWD: /sbin/shutdown -h now
 berwn ALL=(ALL) NOPASSWD: /sbin/reboot