Update branding from Engine Cloud to Transactions (#7516)

Co-authored-by: Cursor Agent <cursoragent@cursor.com>

Author: saminacodes

apps/portal/src/app/Header.tsx

@@ -137,7 +137,7 @@ const apisLinks = [
   },
   {
     href: "https://engine.thirdweb.com/reference#tag/write",
-    name: "Engine Cloud",
+    name: "Transactions",
   },
   {
     href: "https://bridge.thirdweb.com/reference",

apps/portal/src/app/dotnet/wallets/providers/engine-wallet/page.mdx

@@ -8,7 +8,7 @@ export const metadata = createMetadata({
 
 # EngineWallet.Create
 
-A .NET integration of thirdweb [Engine](https://thirdweb.com/engine).
+A .NET integration of thirdweb Transactions.
 
 Instantiate a `Engine` with a given private key. This wallet is capable of signing transactions and messages, interacting with smart contracts, and performing other blockchain operations. **This wallet type is intended for backend applications only,** due to the sensitive nature of private keys.