style: MPS-24 — checksum report asset label 'Product file' -> 'Product'

Operator: the row label should just say 'Product', not 'Product file'.
Template copy only; no test pins the string.

make_post_sell/templates/content.j2

@@ -159,7 +159,7 @@
       <table class="checksum-table">
         <tr><th>Asset</th><th>Algorithm</th><th>Hash</th></tr>
         {% for label, src in [
-            ("Product file", fc.get("product", {})),
+            ("Product", fc.get("product", {})),
             ("Thumbnail", fc.get("thumbnail1", {})),
             ("Title", tc.get("title", {})),
             ("Description", tc.get("description", {})),