feat(falukant): add improve lover affection feature and localization updates

- Introduced the `improveLoverAffection` method in FalukantService to enhance relationship dynamics by allowing users to boost affection at a cost.
- Updated FalukantController and FalukantRouter to include the new endpoint for improving lover affection.
- Enhanced FamilyView component to provide a button for users to trigger the affection improvement action.
- Added localization entries for the new feature in multiple languages, ensuring clarity in user interactions regarding affection improvements.

frontend/src/i18n/locales/en/falukant.json

@@ -942,6 +942,10 @@
                     "maintenanceHigh": "Maintenance 75",
                     "maintenanceSuccess": "Maintenance has been updated.",
                     "maintenanceError": "Maintenance could not be updated.",
+                    "improveAffection": "Boost affection ({cost})",
+                    "improveAffectionHint": "Raises affection, costs money, and also increases visibility.",
+                    "improveAffectionSuccess": "Affection has been strengthened ({cost}). New values: affection {affection}, visibility {visibility}, discretion {discretion}.",
+                    "improveAffectionError": "Affection could not be improved.",
                     "acknowledge": "Acknowledge",
                     "acknowledgeSuccess": "The relationship has been officially acknowledged.",
                     "acknowledgeError": "The relationship could not be acknowledged.",