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-media-replace/classes/DialogUtil.php

@@ -1,29 +0,0 @@
-<?php
-
-// Do not call until Grav 'twig' is initialized and the base twig extensions are loaded.
-function addModalForm($jsid, $twigName)
-{
-    //TODO parametize
-    $bpNewPage = new \Grav\Common\Data\Blueprint("media-replace.yaml");
-    $bpNewPage->setContext(__DIR__ . "/../blueprints");
-    $bpNewPage = $bpNewPage->load()->init();
-
-    $params = [];
-    $params["remodalId"] = $jsid;
-    $params["fields"] = $bpNewPage->toArray()['form']['fields'];
-
-    $grav = \Grav\Common\Grav::instance();
-    $rendered = $grav['twig']->twig()->render($twigName, $params);
-    $arr = [
-        'MODAL' => $rendered
-    ];
-
-    $grav['assets']->addInlineJs("var $jsid = " . json_encode($arr) . ';', -1000, false);
-
-    $modalReg = "
-    $(function () {
-        $('body').append($jsid.MODAL);
-    });";
-    $grav['assets']->addInlineJs($modalReg, -999, false);
-
-}