refactor: replace generic catalog DTOs with shape-typed DTOs for type safety

Replace the single CatalogMaterialDto + CatalogDimensionsDto (bag of nullable
fields) with per-shape DTOs that have strongly-typed dimension properties.
Catalog JSON now groups materials by shape key instead of a flat array.
Delete the old SeedController/SeedDataDtos (superseded by CatalogService).
Scraper updated to emit the new grouped format, resume by default, and
save items incrementally.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

scripts/AlroCatalog/alro-scrape-progress.json

@@ -4,6 +4,11 @@
       "Bars",
       "A-36",
       "ROUND"
+    ],
+    [
+      "Bars",
+      "A-36",
+      "FLAT"
     ]
   ],
   "items": [