[Feature] Add Chainlist link and update header styles (thirdweb-dev#3899

)

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## PR-Codex overview
The focus of this PR is to add a new link "Chainlist" to the dashboard header and update styles for better user experience.

### Detailed summary
- Added "Chainlist" link to the dashboard header
- Updated styles for the "Chainlist" link to match the design
- Adjusted styles for active links in the header for better visibility and consistency

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<!-- end pr-codex -->

apps/dashboard/src/app/components/Header/DashboardHeader.tsx

@@ -27,8 +27,8 @@ export function DashboardHeader() {
               key={link.href}
               href={link.href}
               target={link.href.startsWith("https") ? "_blank" : undefined}
-              className="text-foreground font-medium py-2 px-[10px] hover:underline"
-              activeClassName="font-semibold"
+              className="text-secondary-foreground font-medium py-2 px-[10px] hover:text-foreground"
+              activeClassName="font-medium text-foreground"
             >
               {link.name}
             </NavLink>
@@ -45,7 +45,7 @@ export function DashboardHeader() {
                 key={link.href}
                 href={link.href}
                 target={link.href.startsWith("https") ? "_blank" : undefined}
-                className="text-foreground font-medium py-2 px-[10px] hover:underline"
+                className="text-secondary-foreground font-medium py-2 px-[10px] hover:text-foreground"
               >
                 {link.name}
               </Link>

apps/dashboard/src/app/components/Header/headerLinks.ts

@@ -12,6 +12,10 @@ export const headerLinks = {
       name: "Engine",
       href: "/dashboard/engine",
     },
+    {
+      name: "Chainlist",
+      href: "/chainlist",
+    },
     {
       name: "Settings",
       href: "/dashboard/settings/api-keys",

apps/dashboard/src/components/layout/app-shell/index.tsx

@@ -224,6 +224,17 @@ const AppHeader: React.FC = () => {
           >
             Engine
           </LinkButton>
+          <LinkButton
+            href="/chainlist"
+            isActive={pathname === "/chainlist"}
+            _active={{
+              bg: "bgBlack",
+              color: "bgWhite",
+            }}
+            rounded="lg"
+          >
+            Chainlist
+          </LinkButton>
           <LinkButton
             href="/dashboard/settings/api-keys"
             isActive={pathname.startsWith("/dashboard/settings")}