v4.0: Update nav version badge + add Q&A link

web/components/nav.tsx

@@ -2,7 +2,7 @@
 
 import Link from "next/link";
 import { usePathname } from "next/navigation";
-import { ShieldCheck, Menu, X, Crown, GitCompare } from "lucide-react";
+import { ShieldCheck, Menu, X, Crown, GitCompare, MessageSquare } from "lucide-react";
 import { useState, useEffect } from "react";
 import { createClient } from "@/lib/supabase/client";
 
@@ -27,7 +27,6 @@ export function Nav() {
       const user = data.user;
       setUserEmail(user?.email || null);
       if (user) {
-        // Fetch role from database — no hardcoded emails
         const { data: profile } = await supabase
           .from("profiles")
           .select("role")
@@ -44,7 +43,7 @@ export function Nav() {
         <Link href="/" className="flex items-center gap-2">
           <ShieldCheck className="w-5 h-5 text-zinc-900" strokeWidth={2.2} />
           <span className="font-semibold text-[15px] tracking-tight text-zinc-900">ClauseGuard</span>
-          <span className="hidden sm:inline text-[10px] font-medium text-zinc-400 ml-1 border border-zinc-200 px-1.5 py-0.5 rounded">v3.0</span>
+          <span className="hidden sm:inline text-[10px] font-medium text-zinc-400 ml-1 border border-zinc-200 px-1.5 py-0.5 rounded">v4.0</span>
         </Link>
 
         <div className="hidden md:flex items-center gap-1">