migrate: OfferDialog.vue to use () API

- Replace settings.activeDid with () pattern
- Maintains backward compatibility with existing functionality
- Component now uses active_identity table as single source of truth
- Part of ActiveDid migration (1/32 components completed)

src/components/OfferDialog.vue

@@ -175,7 +175,10 @@ export default class OfferDialog extends Vue {
 
       const settings = await this.$accountSettings();
       this.apiServer = settings.apiServer || "";
-      this.activeDid = settings.activeDid || "";
+
+      // Get activeDid from active_identity table (single source of truth)
+      const activeIdentity = await this.$getActiveIdentity();
+      this.activeDid = activeIdentity.activeDid || "";
 
       // eslint-disable-next-line @typescript-eslint/no-explicit-any
     } catch (err: any) {