Add CSV export for orders and update UI symbols

Introduces an exportOrdersToCSV function in lib/api-client.ts to allow exporting orders by status as a CSV file. Updates various UI components to use the '•' (bullet) symbol instead of '·' (middle dot) and replaces some emoji/unicode characters for improved consistency and compatibility. Also normalizes the 'use client' directive to include a BOM in many files.

components/admin/RecentOrdersCard.tsx

@@ -1,4 +1,4 @@
-"use client";
+"use client";
 import { useEffect, useState } from "react";
 import { fetchClient } from "@/lib/api-client";
 
@@ -81,7 +81,7 @@ export default function RecentOrdersCard() {
                 </div>
               </div>
               <div className="mt-1 text-xs text-muted-foreground">
-                User: {o.userId} · Total: £{Number(o.total).toFixed(2)}
+                User: {o.userId} • Total: £{Number(o.total).toFixed(2)}
               </div>
               {o.items && o.items.length > 0 && (
                 <ul className="mt-2 text-xs list-disc pl-4 text-muted-foreground">