SEO record links; story markets repair; story page titles

Kev's keyword CSV and TYPO3 hold the same solutions under slightly
different names, so the structure check filed them as missing/extra.
Matching is now slug -> normalized title -> record alias, using the
per-model alias store the import tabs got on 2026-08-18
(tx_vitec_import_mapping.record_aliases, key = lowercased CSV name).
One link therefore serves the import union list, the structure check
and vitec:create-markets (same service - linked rows are no longer
proposed as new records).

- every "Missing in TYPO3" row carries a select of all records the
  direct match did not claim; "Save record links" persists per model
- alias-matched rows show under "Both" with a "linked" badge and the
  same select; option 0 removes the link
- SeoResearchService::recordsCheck() additionally returns `linkable`
  (the select options) and flags alias matches with via=link
- new backend POST route seo_aliases

Success stories: --markets-only repair mode
- /success-stories emitted empty `markets` for all 48 stories - a data
  problem (code and TCA untouched since 17.08.); read-only diagnosis
  script migrations/check_usecase_markets.php added
- vitec:import-success-stories --markets-only re-derives each story's
  industries from the export exactly like the full import and rewrites
  ONLY the markets MM relation of the existing record via DataHandler;
  nothing else is touched, no usecase created or deleted, unresolved
  stories keep their current relations
- decision: industries are translated onto the nine main markets of
  the current taxonomy (INDUSTRY_TO_MARKET) instead of recreating the
  seven deleted industry markets; the repair mode never creates
  market records (root cause: those industry markets were deleted
  after the 07.08. taxonomy import, orphaning all story relations)
- ensureMarkets() gained a $create flag for reuse by the full import

Story detail pages: real page title
- every story page answered with the generic page title "Story"; same
  defect and same fix as the product pages on 21.08.: new
  UsecasePageTitleProvider (singleton), registered as vitecUsecase in
  config.pageTitleProviders, fed from UsecaseShowJsonRenderer with
  seo_title falling back to title

Requires on the server:
    vendor/bin/typo3 cache:flush

packages/vitec/Classes/PageTitle/UsecasePageTitleProvider.php

@@ -0,0 +1,33 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Evomedien\Vitec\PageTitle;
+
+use TYPO3\CMS\Core\PageTitle\AbstractPageTitleProvider;
+use TYPO3\CMS\Core\SingletonInterface;
+
+/**
+ * Page title for the success-story detail page - without this every story
+ * answers with the generic page title "Story".
+ *
+ * Singleton on purpose, same reasoning as ProductPageTitleProvider: the
+ * UsecaseShowJsonRenderer that sets the title and the
+ * PageTitleProviderManager that later reads it both obtain the provider via
+ * GeneralUtility::makeInstance(); without the singleton those are two
+ * different instances and the title is never seen by the manager.
+ */
+final class UsecasePageTitleProvider extends AbstractPageTitleProvider implements SingletonInterface
+{
+    private string $seotitle = '';
+
+    public function setSeoTitle(string $seotitle): void
+    {
+        $this->seotitle = $seotitle;
+    }
+
+    public function getTitle(): string
+    {
+        return $this->seotitle;
+    }
+}