Add language-search component for Autre Langue input + active search in lists

Mirrors the mots-clé tag-search system: dropdown suggestions from
existing languages via HTMX, pill display with bin-icon remove buttons,
'Créer' option for new languages. Replaces the plain text input.

- New partial: templates/partials/form/language-search.php
- New fragment: public/partage/language-search-fragment.php
- Admin wrapper: public/admin/language-search-fragment.php
- Updated language-autre-fragment to return just the required asterisk indicator
- Updated both controllers to handle language_autre as array (pill-based)
  with backward-compatible string path
- Updated edit form to compute selectedOtherLanguages from DB
- Registered new route in partage/index.php
- Fix CSV importer: split comma-separated language column into individual entries
- Add htmx active search to admin index, title line-clamp, predefined languages only in checkboxes
- Admin index: filter form now uses htmx triggers (input delay:300ms on search,
  change on selects) to actively search without page reload
- Sort links include hx-push-url for back-button support
- Added loading indicator bar (.admin-search-indicator)
- Title column: line-clamp at 2 lines with overflow hidden, native title attr
  tooltip for full text
- Language checkboxes now show only 3 predefined languages (Français, Anglais,
  Néerlandais); all others go via the Autre langue search component
- Added Database::getPredefinedLanguages() and excluded predefined from
  language-search-fragment suggestions
- Included hidden sort/dir inputs in table-wrap so sort state preserved across
  filter changes
- Fix language-search: block 'Créer' for predefined languages in dropdown
  The 'Créer' option in the language-search dropdown now also checks against the
  predefined set (français, anglais, néerlandais) to avoid offering creation of
  languages that already exist as checkboxes.

app/templates/admin/acces.php

@@ -100,6 +100,19 @@
 +%%%%%%% diff from: somsyvxz 249f7943 "Bulk bar anti-shift, tags icons, AP no-wrap, credits reorder" (rebased revision)
 +\\\\\\\        to: sttrwkly ec5606f5 "CSV importer: boolean and ap variants/typos" (rebased revision)
 ++                        $linkName = $link['name'] ?? '';
+++                        $linkExpiresVal = $link['expires_at'] ? date('Y-m-d\TH:i', strtotime($link['expires_at'])) : '';
+%%%%%%%%%%%%%%%%%%%%%%%%%%% diff from: sttrwkly ec5606f5 "CSV importer: boolean and ap variants/typos" (rebased revision)
+\\\\\\\\\\\\\\\\\\\\\\\\\\\        to: somsyvxz 249f7943 "Bulk bar anti-shift, tags icons, AP no-wrap, credits reorder" (rebased revision)
+-                        $linkName = $link['name'] ?? '';
+-                        $linkExpiresVal = $link['expires_at'] ? date('Y-m-d\TH:i', strtotime($link['expires_at'])) : '';
+%%%%%%%%%%%%%%%%%%%%%%%%%%% diff from: somsyvxz 14a3cd10 "Bulk bar anti-shift, tags icons, AP no-wrap, credits reorder" (rebase destination)
+\\\\\\\\\\\\\\\\\\\\\\\\\\\        to: qxuprqpt da941497 "Add language-search component for Autre Langue input + active search in lists" (rebased revision)
+                         $linkName = $link['name'] ?? '';
+                         $linkExpiresVal = $link['expires_at'] ? date('Y-m-d\TH:i', strtotime($link['expires_at'])) : '';
+                         $linkLockedYear = $link['locked_year'] ?? null;
++%%%%%%% diff from: somsyvxz 249f7943 "Bulk bar anti-shift, tags icons, AP no-wrap, credits reorder" (rebased revision)
++\\\\\\\        to: qxuprqpt a1b3064d "Add language-search component for Autre Langue input + active search in lists" (rebased revision)
+++                        $linkName = $link['name'] ?? '';
 ++                        $linkExpiresVal = $link['expires_at'] ? date('Y-m-d\TH:i', strtotime($link['expires_at'])) : '';
                     ?>
                     <tr class="admin-table-row" onclick="event.stopPropagation(); window.open('/partage/<?= urlencode($link['slug']) ?>', '_blank')" style="cursor:pointer">