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

versioning/templates/partials/activity_table_body.html

@@ -1,7 +1,7 @@
 {% load to_class_name from filters %}
 <div class="table-responsive">
     <table class="table table-striped">
-        <thead class="thead-dark">
+        <thead class="table-dark">
         <tr>
             <th scope="col">Date</th>
             <th scope="col">Object</th>

versioning/templates/partials/version_changes.html

@@ -1,9 +1,9 @@
 {% if version.changes.anything_changed %}
     {% for change in version.changes.field_changes %}
-        <span title="Changes to {{ change.field.verbose_name }}" class="bg-info rounded p-1" data-container="body" data-html="true" data-trigger='hover' data-toggle="popover" data-content='{% spaceless %}{% include "partials/version_changes_change.html" %}{% endspaceless %}'>{{ change.field.verbose_name }}</span>
+        <span title="Changes to {{ change.field.verbose_name }}" class="bg-info rounded p-1" data-bs-container="body" data-bs-html="true" data-bs-trigger='hover' data-bs-toggle="popover" data-bs-content='{% spaceless %}{% include "partials/version_changes_change.html" %}{% endspaceless %}'>{{ change.field.verbose_name }}</span>
     {% endfor %}
     {% for itemchange in version.changes.item_changes %}
-        <span title="Changes to {{ itemchange.name }}" class="bg-info rounded p-1" data-container="body" data-html="true" data-trigger='hover' data-toggle="popover" data-content='{% spaceless %}
+        <span title="Changes to {{ itemchange.name }}" class="bg-info rounded p-1" data-bs-container="body" data-bs-html="true" data-bs-trigger='hover' data-bs-toggle="popover" data-bs-content='{% spaceless %}
             <ul class="list-group list-group-flush">
             {% for change in itemchange.field_changes %}
                   <li class="list-group-item">

versioning/templates/partials/version_history_table.html

@@ -1,7 +1,7 @@
 {% load to_class_name from filters %}
 <div class="table-responsive">
     <table class="table table-striped">
-        <thead class="thead-dark">
+        <thead class="table-dark">
         <tr>
             <th scope="col">Date</th>
             <th scope="col">Version ID</th>

versioning/templates/partials/version_scripts.html

@@ -1,15 +1,2 @@
 {% load static %}
-<script src="{% static "js/tooltip.js" %}"></script>
-<script src="{% static "js/popover.js" %}"></script>
 <script src="{% static "js/moment.js" %}"></script>
-<script>
-    $(function () {
-            $('[data-toggle="tooltip"]').tooltip();
-    });
-    const whiteList = $.fn.tooltip.Constructor.Default.whiteList;
-    whiteList.ins = []
-    whiteList.del = []
-    $(function() {
-        $('[data-toggle="popover"]').popover({whiteList: whiteList});
-    });
-</script>