Add rebuild_sprites after cPanel plugin install

cPanel requires sprite rebuild for new icons to appear in the interface.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

scripts/install.sh

@@ -122,6 +122,8 @@ if [[ -d "$CPANEL_BASE" ]]; then
     tar -czf "$PLUGIN_TMPDIR/gniza-cpanel.tar.gz" -C "$PLUGIN_TMPDIR" install.json gniza/assets/gniza-cpanel-icon.svg
     /usr/local/cpanel/scripts/install_plugin "$PLUGIN_TMPDIR/gniza-cpanel.tar.gz" 2>/dev/null || true
     rm -rf "$PLUGIN_TMPDIR"
+    # Rebuild icon sprites so the new icon appears in cPanel
+    /usr/local/cpanel/bin/rebuild_sprites 2>/dev/null || true
     echo "cPanel user plugin installed — users will see gniza Restore in Files section"
 else
     echo "cPanel not detected, skipping cPanel user plugin installation."