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/form/templates/forms/fields/value/value.html.twig

@@ -1,18 +0,0 @@
-{% extends "forms/field.html.twig" %}
-
-{% if field.options %}
-  {% set value = field.options[value] ?: value %}
-{% endif %}
-
-{% block input %}
-  <span class="field-value">
-    {% switch field.filter %}
-      {% case 'date' %}
-         {{ value|date }}
-      {% case 'raw' %}
-         {{ value|raw }}
-      {% default %}
-         {{ value }}
-    {% endswitch %}
-  </span>
-{% endblock %}