fix(catalog): correct sku_l10 to 400g and enroll its packshot

Ajinomoto ピュアセレクト マヨネーズ has no 450g size: the official lineup is
250g/400g/600g/1kg, the shelf tag in add/image6.jpg reads 400g, and DECISION.md
already recorded the mismatch. Both CSVs carried 450g, so every l10 answer
shipped a wrong size.

The packshot is the exact 400g front (JAN 4901001114030, 1000x1000) with its
source URL and the 450g rejection recorded in
data/packshots/research/sku_l10/manifest.json.

Enrolling it moves the catalog ceiling from 69% to 87% of in-catalog facings
answerable by image (l10 was 11 unenrolled facings). Measured on the corrected
image6 labels: local lane 92% identity at 84% precision full, 85% at 91% live.

Also points external-eval defaults at the repository-local data path; the
licensed Wikimedia corpus remains uncommitted pending manifest review.

recognization/data/packshots/research/sku_l10/manifest.json

@@ -0,0 +1,22 @@
+{
+  "sku": "sku_l10",
+  "canonical_product": "味の素 ピュアセレクト マヨネーズ 400g",
+  "packshot_path": "data/packshots/source/sku_l10.jpg",
+  "source_url": "https://thumbnail.image.rakuten.co.jp/@0_mall/matsukiyo/cabinet/d0042/4901001114030_1.jpg?_ex=1000x1000",
+  "source_page": "https://item.rakuten.co.jp/matsukiyo/4901001114030/",
+  "source_retailer": "楽天市場 / マツモトキヨシ楽天市場店",
+  "jan": "4901001114030",
+  "width": 1000,
+  "height": 1000,
+  "format": "JPEG",
+  "verification": {
+    "visual": "Front packshot visibly reads AJINOMOTO, ピュアセレクト, マヨネーズ, and 400g.",
+    "exact_product": true
+  },
+  "size_correction": {
+    "rejected_size": "450g",
+    "canonical_size": "400g",
+    "reason": "Ajinomoto's official current product page lists 250g, 400g, 600g, and 1kg, not 450g. Archived official Ajinomoto pages from 2008-2014 show the same lineup. The repository shelf photo add/image6.jpg and its shelf tag show ピュアセレクト マヨネーズ 400g; docs/research/2026-09-28-recognition-architecture/DECISION.md records the same mismatch. Retail searches for 450g returned Kewpie products or mixed listings, while JAN 4901001114030 consistently identifies Ajinomoto ピュアセレクト マヨネーズ 400g.",
+    "official_product_page": "https://www.ajinomoto.co.jp/products/detail/?ProductName=pureselect_1"
+  }
+}