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/code/collect_shelf_images.py

@@ -129,7 +129,9 @@ def image_info(titles: list) -> dict:
 
 
 def main() -> None:
-    root = sys.argv[1] if len(sys.argv) > 1 else os.path.expanduser("~/dorayaki-data/shelf-images")
+    default = os.path.join(os.path.dirname(os.path.dirname(os.path.abspath(__file__))),
+                           "data", "external-shelves", "wikimedia-commons")
+    root = sys.argv[1] if len(sys.argv) > 1 else default
     os.makedirs(root, exist_ok=True)
 
     print("searching Commons...")