Backend of the sub-market template (spec agreed section by section with

the customer workflow in mind: the customer fills one XLSX per sub-market,
an importer builds the page).

- Frontend layout 21 'Sub-Market Page' in the existing
  BackendLayoutDataProvider: six zones, one per Figma section, emitted as
  colPos110..colPos160 - the JSON groups plus appearance.layout are the
  front-end contract (spec clause 7.17). A first attempt via page-TSconfig
  BackendLayouts was the wrong mechanism next to the provider and was
  removed again
- New Content Blocks vitec_markethero, vitec_marketintro,
  vitec_marketinsights (field bags, serialized unprefixed under data);
  the workflow section reuses intro-paragraph + vitec_card flip cards
- Stories gained quote/quote_person/quote_role (Testimonial tab),
  maintained once per story, emitted on every story card; usecaselist
  gained the layout value 'testimonials'
- New plugin vitec_productfeature: one referenced product as a full
  product card, serialisation shared with the product list (cObj made
  protected for the subclass)
- vitec_productlist gained hand-picked product selection: exactly the
  chosen products in the editor's order, category filter ignored,
  visibility filters kept - closes the long-standing single-select gap
- New CLI vitec:generate-submarket-workbooks: one protected customer
  XLSX per sub-market (9 main markets, 25 sub-markets from the Market
  category tree) - dropdowns filled live from the database, named ranges
  as the importer contract, hidden Meta sheet pinning submarket/group/
  record uid, soft character-limit warnings, asset URL fields

Verified end to end on Broadcast & Media: layout-21 payload with colPos110
carrying the hero element and its subline. Spec raised to v1.20.

public/_frontend/index.html

@@ -23,8 +23,8 @@
     <meta name="twitter:description" content="Enterprise IPTV, video streaming, and digital signage solutions." />
     <link rel="icon" type="image/svg+xml" href="/fileadmin/icons/favicon.ico" />
     <title>VITEC</title>
-    <script type="module" crossorigin src="/_frontend/assets/index-DnFsTWc9.js"></script>
-    <link rel="stylesheet" crossorigin href="/_frontend/assets/index-D2VJrjll.css">
+    <script type="module" crossorigin src="/_frontend/assets/index-Bp_49Z5l.js"></script>
+    <link rel="stylesheet" crossorigin href="/_frontend/assets/index-Cj1orKsH.css">
   </head>
   <body>
     <div id="page"></div>␍