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-move/templates/move-modal.twig.html

@@ -1,23 +0,0 @@
-<div class="remodal" data-remodal-id="modal-admin-media-move" data-remodal-options="hashTracking: false">
-    <form method="post" onsubmit='return false;'>
-        {% for field in fields %}
-        {% if field.type %}
-        {% set value = data.value(field.name) %}
-        <div class="block block-{{field.type}}">
-            {% include ["forms/fields/#{field.type}/#{field.type}.html.twig", 'forms/fields/text/text.html.twig'] %}
-        </div>
-        {% endif %}
-        {% endfor %}
-
-        <div class="form-field grid">Select a destination page or enter the destination page route.</div>
-
-        <div class="button-bar">
-            <div class="loading">
-                {{ "Moving" }}... <i class="fa fa-spinner fa-spin"></i>
-            </div>
-
-            <button class="button primary" style="visibility: hidden" name="move">{{ "Move" }}</button>
-            <button class="button" style="visibility: hidden" name="move_and_go">{{ "Move And Go" }}</button>
-        </div>
-    </form>
-</div>