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/pages/page/index.js

@@ -1,47 +0,0 @@
-import $ from 'jquery';
-import './add';
-import './move';
-import './delete';
-import './unset';
-import './disable-buttons';
-import PageMedia, { Instance as PageMediaInstances } from './media';
-import './multilang';
-
-const switcher = $('input[type="radio"][name="mode-switch"]');
-
-if (switcher) {
-    let link = switcher.closest(':checked').data('leave-url');
-    let fakeLink = $(`<a href="${link}" />`);
-
-    switcher.parent().append(fakeLink);
-
-    switcher.siblings('label').on('mousedown touchdown', (event) => {
-        event.preventDefault();
-
-        // let remodal = $.remodal.lookup[$('[data-remodal-id="changes"]').data('remodal')];
-        let confirm = $('[data-remodal-id="changes"] [data-leave-action="continue"]');
-
-        confirm.one('click', () => {
-            $(global).on('beforeunload._grav');
-            fakeLink.off('click._grav');
-
-            $(event.target).trigger('click');
-        });
-
-        fakeLink.trigger('click._grav');
-    });
-
-    switcher.on('change', (event) => {
-        let radio = $(event.target);
-        link = radio.data('leave-url');
-
-        setTimeout(() => fakeLink.attr('href', link).get(0).click(), 5);
-    });
-}
-
-export default {
-    Media: {
-        PageMedia,
-        PageMediaInstances
-    }
-};