Rename app from "Shoppy" to "Shoppinguin" across codebase and documentation. Handle migration of legacy storage keys.

app.json

@@ -1,7 +1,7 @@
 {
   "expo": {
-    "name": "Shoppy",
-    "slug": "shoppy",
+    "name": "Shoppinguin",
+    "slug": "shoppinguin",
     "version": "1.0.0",
     "orientation": "portrait",
     "userInterfaceStyle": "automatic",
@@ -14,10 +14,10 @@
     "ios": {
       "supportsTablet": true,
       "infoPlist": {
-        "NSCameraUsageDescription": "Shoppy nutzt die Kamera, um Produkt-Barcodes im Supermarkt zu scannen.",
+        "NSCameraUsageDescription": "Shoppinguin nutzt die Kamera, um Produkt-Barcodes im Supermarkt zu scannen.",
         "ITSAppUsesNonExemptEncryption": false
       },
-      "bundleIdentifier": "net.fretux.shoppy"
+      "bundleIdentifier": "net.fretux.shoppinguin"
     },
     "android": {
       "permissions": [
@@ -26,7 +26,7 @@
       "adaptiveIcon": {
         "backgroundColor": "#f7f3ea"
       },
-      "package": "net.fretux.shoppy"
+      "package": "net.fretux.shoppinguin"
     },
     "extra": {
       "eas": {