feat: migrate DiscoverView.vue to use new ActiveDid pattern

Replace `settings.activeDid` with `$getActiveIdentity()` API call.
Updates discover search functionality to use active_identity table.

- Add `const activeIdentity = await this.$getActiveIdentity();`
- Update activeDid assignment in mounted() lifecycle
- Maintain existing search and discovery functionality

✅ TypeScript compilation passes
✅ Linting standards met
✅ Functionality preserved

Part of ActiveDid migration following "One Component + Test Pattern".

src/views/DiscoverView.vue

@@ -415,7 +415,11 @@ export default class DiscoverView extends Vue {
     const searchPeople = !!this.$route.query["searchPeople"];
 
     const settings = await this.$accountSettings();
-    this.activeDid = (settings.activeDid as string) || "";
+
+    // Get activeDid from new active_identity table (ActiveDid migration)
+    const activeIdentity = await this.$getActiveIdentity();
+    this.activeDid = activeIdentity.activeDid || "";
+
     this.apiServer = (settings.apiServer as string) || "";
     this.partnerApiServer =
       (settings.partnerApiServer as string) || this.partnerApiServer;