feat: product search on TYPO3 13

Search page (searchresult plugin), AJAX results and filter panel, the
mobile filter overlay, search links ("Alle anzeigen", menu icon) and
the /reiseauswahl/{name} landing redirects are back. The search bar in
the page header stays out (SearchbarController not ported); on detail
pages the menu icon links to the search page instead of toggling it.

- Extbase requests are immutable: withArgument() instead of
  setArgument()
- StaticSearchParamsMiddleware runs after site resolution and before
  page resolution (the old position is a cycle in v13); FilterService
  copes with the missing TypoScript there, as TYPO3 10 did
- Search and filter forms are sent URL-encoded instead of multipart, so
  production can keep rejecting multipart requests
- ski-wochenenden: websiteTitle from the old sys_template sitetitle

Compared with TYPO3 10 on the same data (249 cases: search pages with
all 41 preset filters, landing redirects, AJAX results and filter
panel, GET and POST): 186 identical, 63 with the same results in a
different order (PHP 8 sorts stably, ties came out in arbitrary order
on PHP 7.4). Processed image names differ by their configuration hash.

Co-Authored-By: Claude Opus 5.5 <[email protected]>

packages/ep_theme/Resources/Private/Partials/Mainnav.html

@@ -17,6 +17,18 @@
                     <f:render section="FirstLevel" arguments="{_all}"/>
                 </div>
                 <div class="flex hover-hover:lg:hidden items-center space-x-4">
+                    <f:if condition="{settings.hideSearchbar}">
+                        <f:else>
+                            <button type="button"
+                                    class="focus:outline-none text-zinc-800"
+                                    aria-label="Reisen suchen"
+                                    data-controller="overlay-toggle"
+                                    data-overlay-toggle-id-value="mobile-search"
+                                    data-action="overlay-toggle#invokeToggle">
+                                {ep:icon(icon: 'search', class: 'w-8 h-8 text-zinc-800')}
+                            </button>
+                        </f:else>
+                    </f:if>
                     <button type="button"
                             class="focus:outline-none text-zinc-800"
                             aria-label="Navigation öffnen"
@@ -61,6 +73,27 @@
                         </f:if>
                     </li>
                 </f:for>
+                <f:if condition="{data.tx_eptheme_hide_searchbar} || {settings.hideSearchbar}">
+                    <f:else>
+                        <li class="pb-4" role="none">
+                            <f:if condition="{searchbarCollapsed}">
+                                <f:then>
+                                    <button type="button"
+                                            aria-label="Suche anzeigen/ausblenden"
+                                            data-controller="searchbar-toggle"
+                                            data-action="searchbar-toggle#toggle">
+                                        {ep:icon(icon: 'search', class: 'w-6 h-6')}
+                                    </button>
+                                </f:then>
+                                <f:else>
+                                    <f:link.typolink parameter="{settings.defaultSearchPageUid}" title="zur Suche" additionalAttributes="{'role': 'menuitem'}">
+                                        {ep:icon(icon: 'search', class: 'w-6 h-6')}
+                                    </f:link.typolink>
+                                </f:else>
+                            </f:if>
+                        </li>
+                    </f:else>
+                </f:if>
             </ul>
         </nav>
     </f:section>