Convert Vue components to use @Emit decorator instead of manual emits declarations

Replace manual emits declarations with proper @Emit decorator usage across components:
- ActivityListItem: Add @Emit methods for viewImage, loadClaim, confirmClaim
- ContactInputForm: Convert handleQRScan to use @Emit("qr-scan")
- ContactBulkActions: Add @Emit methods for toggle-all-selection, copy-selected
- ContactListHeader: Add @Emit methods for all 5 emitted events
- MembersList: Add @Emit("error") method for error handling
- LargeIdenticonModal: Add @Emit("close") method
- ContactListItem: Add @Emit methods for all 4 emitted events

Update all templates to call emit methods instead of direct $emit calls.
Fix TypeScript type issues with optional parameters.
Resolves Vue warning about undeclared emitted events.

Follows vue-facing-decorator best practices and improves code consistency.

src/components/MembersList.vue

@@ -178,7 +178,7 @@
 // Validation: Passes lint checks and TypeScript compilation
 // Navigation: Contacts → Chair Icon → Start/Join Meeting → Members List
 
-import { Component, Vue, Prop } from "vue-facing-decorator";
+import { Component, Vue, Prop, Emit } from "vue-facing-decorator";
 
 import {
   errorStringForLog,
@@ -222,6 +222,12 @@ export default class MembersList extends Vue {
   @Prop({ required: true }) password!: string;
   @Prop({ default: false }) showOrganizerTools!: boolean;
 
+  // Emit methods using @Emit decorator
+  @Emit("error")
+  emitError(message: string) {
+    return message;
+  }
+
   decryptedMembers: DecryptedMember[] = [];
   firstName = "";
   isLoading = true;
@@ -262,10 +268,7 @@ export default class MembersList extends Vue {
         "Error fetching members: " + errorStringForLog(error),
         true,
       );
-      this.$emit(
-        "error",
-        serverMessageForUser(error) || "Failed to fetch members.",
-      );
+      this.emitError(serverMessageForUser(error) || "Failed to fetch members.");
     } finally {
       this.isLoading = false;
     }
@@ -478,8 +481,7 @@ export default class MembersList extends Vue {
         "Error toggling admission: " + errorStringForLog(error),
         true,
       );
-      this.$emit(
-        "error",
+      this.emitError(
         serverMessageForUser(error) ||
           "Failed to update member admission status.",
       );