Add RelationshipChangeLog model and enhance character loading logic

backend/models/index.js

@@ -113,6 +113,7 @@ import Vote from './falukant/data/vote.js';
 import ElectionResult from './falukant/data/election_result.js';
 import PoliticalOfficeHistory from './falukant/log/political_office_history.js';
 import ElectionHistory from './falukant/log/election_history.js';
+import RelationshipChangeLog from './falukant/log/relationship_change_log.js';
 
 // — Kirchliche Ämter (Church) —
 import ChurchOfficeType from './falukant/type/church_office_type.js';
@@ -248,6 +249,7 @@ const models = {
   ElectionResult,
   PoliticalOfficeHistory,
   ElectionHistory,
+  RelationshipChangeLog,
   ChurchOfficeType,
   ChurchOfficeRequirement,
   ChurchOffice,