chore: Version 0.9.21, Android-Build-Tooling und Flutter-Abhängigkeiten aktualisiert

- Version auf 0.9.21 angehoben (App und Backend)
- Gradle 8.14.3, AGP 8.11.1, Kotlin 2.2.20; Flutter-Migrator-Flags in gradle.properties
- camera ^0.12.0, mobile_scanner ^7.0.0
- tsconfig ignoreDeprecations auf 5.0, prod.bundle neu gebaut
- upload.sh entfernt

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>

app/pubspec.yaml

@@ -16,7 +16,7 @@ publish_to: 'none' # Remove this line if you wish to publish to pub.dev
 # https://developer.apple.com/library/archive/documentation/General/Reference/InfoPlistKeyReference/Articles/CoreFoundationKeys.html
 # In Windows, build-name is used as the major, minor, and patch parts
 # of the product and file versions while build-number is used as the build suffix.
-version: 0.9.20+1
+version: 0.9.21+1
 
 environment:
   sdk: ^3.7.0
@@ -56,14 +56,14 @@ dependencies:
   path_provider: ^2.1.5
 
   # Camera for photo tasks (Android/iOS/Web)
-  camera: ^0.10.5+9
+  camera: ^0.12.0
 
   # File selection (mobile uses file_picker; desktop uses file_selector)
   file_picker: ^8.0.6
   file_selector: ^1.0.3
 
   # Barcode scanning for mobile platforms
-  mobile_scanner: ^5.0.0
+  mobile_scanner: ^7.0.0
 
   # Signature drawing canvas for capturing signatures
   signature: ^5.5.0