chore(01-01): scaffold Flutter project with all dependencies and tooling

- Flutter project created with flutter create (Android platform)
- Runtime deps: flutter_riverpod, riverpod_annotation, drift 2.31, drift_flutter, go_router, path_provider, shared_preferences, flutter_localizations, intl
- Dev deps: riverpod_generator, drift_dev 2.31, build_runner
- Pinned drift/drift_dev to 2.31 for analyzer ^9.0.0 compatibility with riverpod_generator
- Configured l10n.yaml, build.yaml (Drift), analysis_options.yaml (riverpod_lint)
- Minimal ARB file for localization tooling to resolve

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

pubspec.yaml

@@ -0,0 +1,33 @@
+name: household_keeper
+description: "Dein Haushalt, entspannt organisiert."
+publish_to: 'none'
+version: 1.0.0+1
+
+environment:
+  sdk: ^3.11.0
+
+dependencies:
+  flutter:
+    sdk: flutter
+  flutter_localizations:
+    sdk: flutter
+  intl: any
+  flutter_riverpod: ^3.3.1
+  riverpod_annotation: ^4.0.2
+  drift: ^2.31.0
+  drift_flutter: ^0.2.8
+  go_router: ^17.1.0
+  path_provider: ^2.1.5
+  shared_preferences: ^2.5.4
+
+dev_dependencies:
+  flutter_test:
+    sdk: flutter
+  flutter_lints: ^6.0.0
+  riverpod_generator: ^4.0.3
+  drift_dev: ^2.31.0
+  build_runner: ^2.4.0
+
+flutter:
+  uses-material-design: true
+  generate: true