fix: persist identity names per user instead of globally

Fixes issue where identity names were not saved when switching between
multiple identities. Names were being saved to master settings instead
of user-specific settings.

Changes:
- UserNameDialog: Load/save names from/to user-specific settings
- NewEditAccountView: Save names to user-specific settings for active DID
- Both components now use $accountSettings() and $saveUserSettings()
  instead of $settings() and $updateSettings()

Each identity now properly retains their assigned name when switching
between identities. Previously only "User Zero" would show their name
due to using master settings instead of per-identity settings.

Fixes: Identity name persistence across identity switches

src/components/UserNameDialog.vue

@@ -84,7 +84,8 @@ export default class UserNameDialog extends Vue {
    */
   async open(aCallback?: (name?: string) => void) {
     this.callback = aCallback || this.callback;
-    const settings = await this.$settings();
+    // Load from account-specific settings instead of master settings
+    const settings = await this.$accountSettings();
     this.givenName = settings.firstName || "";
     this.visible = true;
   }
@@ -95,7 +96,18 @@ export default class UserNameDialog extends Vue {
    */
   async onClickSaveChanges() {
     try {
-      await this.$updateSettings({ firstName: this.givenName });
+      // Get the current active DID to save to user-specific settings
+      const settings = await this.$accountSettings();
+      const activeDid = settings.activeDid;
+      
+      if (activeDid) {
+        // Save to user-specific settings for the current identity
+        await this.$saveUserSettings(activeDid, { firstName: this.givenName });
+      } else {
+        // Fallback to master settings if no active DID
+        await this.$saveSettings({ firstName: this.givenName });
+      }
+      
       this.visible = false;
       this.callback(this.givenName);
     } catch (error) {

src/views/NewEditAccountView.vue

@@ -110,10 +110,24 @@ export default class NewEditAccountView extends Vue {
    * @async
    */
   async onClickSaveChanges() {
-    await this.$updateSettings({
-      firstName: this.givenName,
-      lastName: "", // deprecated, pre v 0.1.3
-    });
+    // Get the current active DID to save to user-specific settings
+    const settings = await this.$accountSettings();
+    const activeDid = settings.activeDid;
+    
+    if (activeDid) {
+      // Save to user-specific settings for the current identity
+      await this.$saveUserSettings(activeDid, {
+        firstName: this.givenName,
+        lastName: "", // deprecated, pre v 0.1.3
+      });
+    } else {
+      // Fallback to master settings if no active DID
+      await this.$saveSettings({
+        firstName: this.givenName,
+        lastName: "", // deprecated, pre v 0.1.3
+      });
+    }
+    
     this.$router.back();
   }