feat: duplicate your own recipe

The fork endpoint already had no "isn't yours" check, so this is a
UI-only change: ForkRecipeButton takes a variant prop ("fork" for
others' recipes, "duplicate" for your own) that swaps icon/label/toast
copy, and now renders unconditionally instead of only for non-owners.

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

apps/web/messages/en.json

@@ -121,6 +121,8 @@
     "forked": "Recipe forked to your library",
     "forkFailed": "Failed to fork recipe",
     "forkLimitReached": "Recipe limit reached for your tier",
+    "duplicateTooltip": "Duplicate this recipe",
+    "duplicated": "Recipe duplicated",
     "forkedFrom": "Forked from {title}",
     "pairingFindingLabel": "Finding perfect pairings…",
     "pairingSuggestButton": "Suggest pairings",