Add heir management functionality in Falukant module

- Implemented setHeir method in FalukantService to designate a child as heir, including validation checks for user and child relationships.
- Updated FalukantController to expose the setHeir endpoint, allowing users to set heirs via the API.
- Enhanced FalukantRouter with a new route for setting heirs.
- Modified FamilyView component to include UI elements for setting heirs, with success and error feedback.
- Updated localization files in both German and English to include new translations related to heir management, improving user experience.

backend/services/falukantService.js

@@ -2391,11 +2391,13 @@ class FalukantService extends BaseService {
             for (const rel of allRels) {
                 const kid = rel.child;
                 children.push({
+                    childCharacterId: kid.id,
                     name: kid.definedFirstName?.name || 'Unknown',
                     gender: kid.gender,
                     age: calcAge(kid.birthdate),
-            hasName: rel.nameSet,
-            _createdAt: rel.createdAt,
+                    hasName: rel.nameSet,
+                    isHeir: rel.isHeir || false,
+                    _createdAt: rel.createdAt,
                 });
             }
         }
@@ -2426,6 +2428,46 @@ class FalukantService extends BaseService {
         return family;
     }
 
+    async setHeir(hashedUserId, childCharacterId) {
+        const user = await this.getFalukantUserByHashedId(hashedUserId);
+        if (!user) throw new Error('User not found');
+        const character = await FalukantCharacter.findOne({ where: { userId: user.id } });
+        if (!character) throw new Error('Character not found for this user');
+
+        // Prüfe, ob das Kind wirklich ein Kind des aktuellen Charakters ist
+        const childRelation = await ChildRelation.findOne({
+            where: {
+                childCharacterId: childCharacterId,
+                [Op.or]: [
+                    { fatherCharacterId: character.id },
+                    { motherCharacterId: character.id }
+                ]
+            }
+        });
+
+        if (!childRelation) {
+            throw new Error('Child not found or not your child');
+        }
+
+        // Setze alle anderen Kinder des gleichen Elternteils auf isHeir = false
+        await ChildRelation.update(
+            { isHeir: false },
+            {
+                where: {
+                    [Op.or]: [
+                        { fatherCharacterId: character.id },
+                        { motherCharacterId: character.id }
+                    ]
+                }
+            }
+        );
+
+        // Setze das ausgewählte Kind als Erben
+        await childRelation.update({ isHeir: true });
+
+        return { success: true, childCharacterId };
+    }
+
     async getPossiblePartners(requestingCharacterId) {
         const proposals = await MarriageProposal.findAll({
             where: {