Success-story migration + new plugins + JSON/UX polish

- Success Stories: full migration from old site (48/48, audited),
  markets n:n, quotation content block, columns content block,
  pretty SEO detail URLs via SuccessStoryPathRewrite middleware,
  list/detail split (list page 4 / story page), detailUrl/backUrl
- New plugins: VITEC Locations (grid/list/map + RTE map text),
  VITEC Customer Logos (color/bw logic, only-show-selected),
  VITEC Card (one plugin for product/story/market/solution
  with reloading FlexForm + custom backend preview renderer)
- Eventlist: layout dropdown (list/grid/teaserbar) in settings
- Hero section CB: Images/Video tabs, background video + overlay
- Product JSON: full category rootline (parents), fixed missing
  ConnectionPool import (all-products crash), category tree map
- Backend preview CSS: container-query responsive (narrow columns)
- Docs: ISO architecture spec, root + extension READMEs

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

composer.json

@@ -22,6 +22,7 @@
 		"friendsoftypo3/headless": "^5.0@rc",
 		"georgringer/news": "^14.0",
 		"netzbewegung/nb-headless-content-blocks": "^0.0.23",
+		"plan2net/backend-category-hierarchy": "^14.0",
 		"typo3/cms-backend": "^14.3",
 		"typo3/cms-belog": "^14.3",
 		"typo3/cms-beuser": "^14.3",