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>

public/_frontend/.htaccess

@@ -1,27 +1,27 @@
-RewriteEngine On
-RewriteBase /_frontend/
-
-RewriteRule ^index\.html$ - [L]
-
-RewriteCond %{REQUEST_FILENAME} -f [OR]
-RewriteCond %{REQUEST_FILENAME} -d
-RewriteRule ^ - [L]
-
-RewriteRule ^ index.html [L]
-
-# ── Cache headers ────────────────────────────────────────────────────────────
-
-# index.html: never cache — always fetch fresh so the browser picks up
-# the latest hashed JS/CSS filenames after a deploy.
-<Files "index.html">
-    Header set Cache-Control "no-store, no-cache, must-revalidate"
-    Header set Pragma "no-cache"
-    Header set Expires "0"
-</Files>
-
-# Hashed assets (JS, CSS, fonts, images inside /assets/):
-# Vite appends a content hash to every filename, so these are immutable.
-# Cache them for 1 year — a new deploy produces new filenames automatically.
-<FilesMatch "\.(js|css|woff2?|ttf|eot|otf)$">
-    Header set Cache-Control "public, max-age=31536000, immutable"
-</FilesMatch>
+RewriteEngine On
+RewriteBase /_frontend/
+
+RewriteRule ^index\.html$ - [L]
+
+RewriteCond %{REQUEST_FILENAME} -f [OR]
+RewriteCond %{REQUEST_FILENAME} -d
+RewriteRule ^ - [L]
+
+RewriteRule ^ index.html [L]
+
+# ── Cache headers ────────────────────────────────────────────────────────────
+
+# index.html: never cache — always fetch fresh so the browser picks up
+# the latest hashed JS/CSS filenames after a deploy.
+<Files "index.html">
+    Header set Cache-Control "no-store, no-cache, must-revalidate"
+    Header set Pragma "no-cache"
+    Header set Expires "0"
+</Files>
+
+# Hashed assets (JS, CSS, fonts, images inside /assets/):
+# Vite appends a content hash to every filename, so these are immutable.
+# Cache them for 1 year — a new deploy produces new filenames automatically.
+<FilesMatch "\.(js|css|woff2?|ttf|eot|otf)$">
+    Header set Cache-Control "public, max-age=31536000, immutable"
+</FilesMatch>