Unify list plugins, add solution list and per-story detail page

- vitec_usecaselist: layout + record selection like marketlist
- new plugin vitec_solutionlist (spec 7.13.3, key "solutions")
- tx_vitec_domain_model_usecase: detail_page -> resolved detailUrl
  (also gives story cards in vitec_modelcard a link for the first time)
- "Show Toolbar" checkbox on product/market/solution/usecase lists
- spec bumped to v1.9

BREAKING: vitec_productlist and vitec_usecaselist now emit an object
instead of a bare array. Consumers must read products.products and
usecases.usecases. Also found: productlist had a configurable layout
that was never serialised; it is emitted now, but keeps its own 0-3
vocabulary instead of grid/list/carousel.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

packages/vitec/Resources/Private/Templates/Solution/List.html

@@ -0,0 +1,9 @@
+<html xmlns:f="http://typo3.org/ns/TYPO3/CMS/Fluid/ViewHelpers" data-namespace-typo3-fluid="true">
+<!--
+    Headless mode: the JSON for vitec_solutionlist is produced by
+    Evomedien\Vitec\UserFunc\SolutionListJsonRenderer, wired in
+    Configuration/TypoScript via the Vitecset setup. This template only exists so
+    SolutionController::listAction() has one to render if the plugin is ever
+    reached through the regular Extbase path.
+-->
+</html>

packages/vitec/Resources/Public/Icons/vitec-plugin-solutionlist.svg

@@ -0,0 +1,8 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24" fill="none"
+     stroke="#26358c" stroke-width="1.8" stroke-linecap="round" stroke-linejoin="round">
+  <rect x="3" y="3.5" width="8" height="8" rx="1.5"/>
+  <rect x="13" y="3.5" width="8" height="8" rx="1.5"/>
+  <rect x="3" y="13.5" width="8" height="7" rx="1.5"/>
+  <rect x="13" y="13.5" width="8" height="7" rx="1.5"/>
+</svg>