Bootstrap 5 & remove jQuery (#661)

* build: move frontend assets to Bootstrap 5.3 and Tom Select

* feat: migrate templates and scripts to Bootstrap 5, dropping jQuery

Templates
- Rename Bootstrap 4 classes and data attributes (data-bs-*, ms-/me-/ps-/pe-,
  text-start/end, form-group -> mb-3, input-group wrappers removed, badges,
  custom controls -> form-check/form-select, media -> d-flex, btn-close, ...)
- Dark mode now uses Bootstrap 5.3 colour modes (data-bs-theme on <html>),
  set from <head> to avoid a flash of the light theme
- Remove the Bootstrap 4 /bootstrap/ demo page
- Contextual table classes (table-success etc.) still work as plain
  backgrounds for the rigboard key

JavaScript
- Remove jQuery: src.js/interaction.js and every inline template script are
  rewritten in plain JS on top of small helpers (helpers.js, bundled with
  Bootstrap into jpop.js so inline scripts can use them)
- Replace bootstrap-select/ajax-bootstrap-select with Tom Select. The remote
  search now sends the `q` parameter and reads `text`, which is what the
  API actually uses (the old picker sent `term` and read `label`)
- HTML fragments are fetched with an X-Requested-With header so views keep
  rendering their modal variants, and fetched scripts are re-executed
- Remove the Bootstrap 4 plugin script includes

* fix: stop rigboard header buttons stretching to full width under Bootstrap 5

* fix: restore dark-mode brand colours and contextual table colours under Bootstrap 5

* fix: brighten dark-mode links and make coloured card outlines visible

* fix: calendar layout and grid borders, navbar search button width, guard missing modal links

* fix: readable text in dark-mode Tom Select inputs and placeholders, restore form-control column widths

* build: split the Dockerfile into cached stages with prod and dev targets

* deploy: make compose.yml development-only with live reload, and document it

* fix: keep badge text colour for links inside badges

* fix: restore table-bordered grid lines in dark mode

* fix: include Bootstrap's progress styles and keep progress labels readable

training/templates/edit_training_record.html

@@ -13,30 +13,22 @@
 {% endblock %}
 
 {% block js %}
-    <script src="{% static 'js/tooltip.js' %}"></script>
 {% endblock %}
 
 {% block content %}
-<script src="{% static 'js/autocompleter.js' %}"></script>
-<script>
-    //Has to be done here or the pickers disappear on modal error
-    $('document').ready(function(){
-        $(document).find(".selectpicker").selectpicker().each(function(){initPicker($(this))});
-    });
-</script>
 <form role="form" action="{{ form.action|default:request.path }}" method="POST" id="add_record_form">
     {% include 'form_errors.html' %}
     {% csrf_token %}
     {% render_field form.trainee|attr:'hidden' value=form.trainee.initial %}
     {% include 'partials/item_field.html' %}
-    <div class="form-group form-row">
+    <div class="mb-3 row g-2">
       <label for="depth" class="col-sm-2 col-form-label">Depth</label>
-      {% render_field form.depth|add_class:'form-control custom-select col-sm-8' %}
+      {% render_field form.depth|add_class:'form-control form-select col-sm-8' %}
     </div>
-    <div class="form-group form-row">
+    <div class="mb-3 row g-2">
       {% include 'partials/supervisor_field.html' %}
     </div>
-    <div class="form-group form-row">
+    <div class="mb-3 row g-2">
         <label for="date" class="col-sm-2 col-form-label">Training Date</label>
         <div class="col-sm-8">
             {% with training_date=object.date|date:"Y-m-d" %}
@@ -45,14 +37,14 @@
         </div>
         {% button 'today' id='id_date' %}
     </div>
-    <div class="form-group form-row">
+    <div class="mb-3 row g-2">
         <label for="id_notes" class="col-sm-2 col-form-label">Notes</label>
         <div class="col-sm-8">
         {% render_field form.notes|add_class:'form-control' rows=3 %}
         </div>
     </div>
   {% if not is_ajax %}
-   <div class="col-sm-12 text-right pr-0">
+   <div class="col-sm-12 text-end pe-0">
         {% button 'submit' %}
     </div>
   {% endif %}
@@ -60,7 +52,7 @@
 {% endblock %}
 
 {% block footer %}
-<div class="col-sm-12 text-right pr-0">
+<div class="col-sm-12 text-end pe-0">
 <button type="submit" class="btn btn-primary" title="Save" form="add_record_form"><span class="fas fa-save align-middle"></span> <span class="d-none d-sm-inline align-middle">Save</span></button>
 </div>
 {% endblock %}