Move plugins to manifest, pin Docker version, add Makefile

- Add plugins.txt listing all plugins for reproducible installs
- Add Makefile with setup/start/stop/install-plugins targets
- Remove user/plugins/ from git tracking
- Pin Docker image to 1.7.49.5-ls244

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

plugins/admin/themes/grav/app/forms/fields/range.js

@@ -1,10 +0,0 @@
-import $ from 'jquery';
-
-$(document).on('input', '[type="range"].rangefield, [type="number"].rangefield', (event) => {
-    const target = $(event.currentTarget);
-    const type = target.attr('type').toLowerCase();
-    const sibling = type === 'range' ? 'number' : 'range';
-    const feedback = target.siblings(`[type="${sibling}"].rangefield`);
-
-    feedback.val(target.val());
-});