Add dashboard navigation and request timeouts

Added 'Back to Dashboard' buttons to all admin dashboard pages for improved navigation. Introduced AbortSignal timeouts to API client and middleware requests to prevent hanging network calls. Also enabled messaging customers from the order details page if Telegram info is available.

app/dashboard/admin/invite/page.tsx

@@ -10,6 +10,7 @@ import { Select, SelectContent, SelectItem, SelectTrigger, SelectValue } from "@
 import { Badge } from "@/components/ui/badge";
 import { UserPlus, Mail, Copy, Check } from "lucide-react";
 import { useState } from "react";
+import Link from "next/link";
 
 export default function AdminInvitePage() {
   const [inviteData, setInviteData] = useState({
@@ -35,9 +36,14 @@ export default function AdminInvitePage() {
 
   return (
     <div className="space-y-6">
-      <div>
-        <h1 className="text-2xl font-semibold tracking-tight">Invite Vendor</h1>
-        <p className="text-sm text-muted-foreground mt-1">Send invitations to new vendors to join the platform</p>
+      <div className="flex items-center justify-between">
+        <div>
+          <h1 className="text-2xl font-semibold tracking-tight">Invite Vendor</h1>
+          <p className="text-sm text-muted-foreground mt-1">Send invitations to new vendors to join the platform</p>
+        </div>
+        <Button asChild variant="outline" size="sm">
+          <Link href="/dashboard">Back to Dashboard</Link>
+        </Button>
       </div>
 
       <div className="grid gap-6 lg:grid-cols-2">