Datapath stories, grid repairs, menu v2 pure, hero placeholders, fec test

Batch of 2026-10-28/29 plus 2026-11-03:

- NEW vitec:import-datapath-stories: 22 story packages from the agency
  dump (docx + Links/ assets) as usecase records with content, quotes,
  images, customer logos, download cards; --repair-quotes normalizes
  attribution lines; asset backfill for existing stories
- /products grid incident repaired (fix_products_grid, fix_graphics_grid,
  check_grid_page): containers unhidden, 46 duplicate cards soft-deleted,
  section order restored; BuildProductPortfolio and
  ImportProductCategoryPages now GUARD against re-runs on pages that
  already carry vitec_cols_% containers
- ' double-encoding fixed: render-pipeline importers write literal
  apostrophes (ENT_NOQUOTES), fix_double_entities literalizes existing rows
- ticket quick wins (ticket_quickwins_20261028), broadcast market page
  cleanup, AttachCardImages market-card handling, SubmarketWorkbook
  META REPAIR, story content/video fixes (fix_story_*)
- ProvideProductCatalog: transitional v1 fields removed (categories
  uid/link, legacyGroupFields, item products teaser) - pure v2 shape
  (ticket 0024-FE); search renderer keeps its teaser
- BuildProductOverviews: heroes get the numbered placeholder background
  (placeholders/pages/<uid>-01.png, wide grey fallback) - backfill on
  existing pages with empty hero_bgimage, attached at creation for new
  pages; existing references always win (ticket 0026-FE); 40 placeholder
  PNGs shipped to fileadmin (not tracked)
- AttachPageMedia: --depth=3 with sysfolders as pass-through parents for
  the overview pages' -08 menu tiles
- NEW migrations/fec_isolation_test.sh: two-user live test proving
  fe_comment ticket isolation (backend verified tight, cross-user
  sighting traced to the FE page-JSON cache, ticket 0027-BE)

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

.gitignore

@@ -140,3 +140,4 @@ migrations/product_categories_xlsx_in/
 
 # generated internal report (php migrations/build_product_audit.php)
 public/product-audit/
+migrations/datapath_stories_in/