1.2.0: offer code redemption + share link alongside export image

- "Redeem promo code" button in PremiumView via offerCodeRedemption
  (hidden on Mac where the sheet is unavailable); entitlement re-checked
  on success — unblocks influencer/blog promo campaigns
- System share sheet now includes a localized text with the mealmood.app
  link next to the exported image (viral loop no longer QR-only)
- 2 new strings × 6 languages

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01UtWT52pAE91D7mbDda1cAM

MealMood/Views/Home/SocialShareSheet.swift

@@ -62,7 +62,9 @@ struct SocialShareSheet: View {
         }
         .toast(isShowing: $showCopiedToast, message: String(localized: "share_copied"))
         .sheet(isPresented: $showSystemShare) {
-            SystemShareSheet(activityItems: [imageURL])
+            // Ship the link as text alongside the image so the viral loop isn't
+            // limited to the QR baked into the rendered export.
+            SystemShareSheet(activityItems: [imageURL, String(localized: "share_link_text")])
         }
     }