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/templates/forms/fields/element/element.html.twig

@@ -1,23 +0,0 @@
-{% extends "forms/field.html.twig" %}
-
-{% block field %}
-  {% set parent = parent_name|parent_field %}
-  {% set plain_name = (field.plain_name ?? field.name)|string %}
-  {% set name = parent ~ '.' ~ plain_name %}
-  {% if field.field %}
-    {% set fields = prepare_form_fields({(name): field.field}) %}
-  {% else %}
-    {% set fields = prepare_form_fields(field.fields, name) %}
-  {% endif %}
-
-  {% embed 'forms/default/fields.html.twig' with {name: name, fields: fields} %}
-    {% set initial_state = plain_name is not same as (parent_value|string) ? 'display: none;' %}
-    {% block outer_markup_field_open %}
-      <div id="{{ parent_name ~ '__' ~ plain_name }}" class="form-element" style="{{ initial_state }}">
-    {% endblock %}
-
-    {% block outer_markup_field_close %}
-        </div>
-    {% endblock %}
-  {% endembed %}
-{% endblock %}