Pick the site icon from the library and crop it, find legal pages by search, list newest first

- The site icon is no longer a select at the end of the company data. It has
  its own section: a button opens the media library (upload included), then
  a square is dragged, resized by its corner, a slider or +/-, and previewed
  at 180 and 32 px. The crop is stored as fractions (faviconCrop) and the
  PNGs are cut from it; faviconVersion changes the link so browsers pick up
  a new cut. Icons without a crop keep their old link.
- openMedia() takes needsAlt: false, since the icon never appears as
  content. The dialog styles moved from editor.css to media-dialog.css so
  the dialog works outside the editor.
- Privacy page and imprint are chosen with the content search, like the 404
  page. The picker can store the path instead of the id (valueKey/data-value).
- The page and post lists in the administration sort newest first; the
  subpage indentation is gone there, as it would point at the wrong parent.

Tests: 581 PHPUnit, 35 node, test:editor green (the consent step now picks
the privacy page by search). test:admin --admin-only fails only at the known
nested-interactive menu summaries.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

templates/admin/content-picker.html.twig

@@ -1,11 +1,11 @@
 {% set selected = selected|default(null) %}
-<div class="content-picker" data-source="{{ path('admin_content_choices') }}" data-type="{{ type|default('') }}" data-parents="{{ parents|default(false) ? '1' : '0' }}">
+<div class="content-picker" data-source="{{ path('admin_content_choices') }}" data-type="{{ type|default('') }}" data-parents="{{ parents|default(false) ? '1' : '0' }}"{% if valueKey|default('id') != 'id' %} data-value="{{ valueKey }}"{% endif %}>
     <label for="{{ id }}">{{ label|default('Seite suchen') }}</label>
     <div class="picker-input">
         <input id="{{ id }}" type="search" autocomplete="off" role="combobox" aria-autocomplete="list" aria-expanded="false" aria-controls="{{ id }}-results" placeholder="Titel oder Adresse suchen …" value="{{ selected ? selected.title ~ ' (/' ~ selected.path ~ ')' : '' }}">
         <button type="button" class="subtle picker-clear" aria-label="{{ label|default('Seite') }}: Auswahl entfernen">✕</button>
     </div>
-    <input type="hidden" class="picker-value" name="{{ name }}" value="{{ selected ? selected.id : '' }}">
+    <input type="hidden" class="picker-value" name="{{ name }}" value="{{ selected ? attribute(selected, valueKey|default('id')) : '' }}">
     <div id="{{ id }}-results" class="picker-results" role="listbox" aria-label="Suchergebnisse" hidden></div>
     <p class="picker-status field-help" role="status"></p>
 </div>