[portal] added module warning (#6590)

CORE-0000

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## PR-Codex overview
This PR adds a warning callout to the `page.mdx` file in the `cross-chain/agglayer` directory, informing users that the Agglayer module is in beta and has deployment limitations.

### Detailed summary
- Added a warning callout indicating that the Agglayer module is in beta.
- Specified that deployments are limited to `Sepolia` and `Cardona` due to requirements for Ethereum as L1 and zkEVM as L2.

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Author: saminacodes

apps/portal/src/app/contracts/modular-contracts/module-contracts/cross-chain/agglayer/page.mdx

@@ -16,6 +16,10 @@ interoperable smart contract for trustless and secure transfers across any chain
 
 Learn how to add the Agglayer module to your modular contract and enable cross-chain transfers.
 
+<Callout variant="warning" title="Beta Module">
+This module is currently in beta while the Agglayer bridge is not live in implementation. This means deployments are limited to Sepolia and Cardona as it requires Ethereum as an L1 and zkEVM as L2.
+</Callout>
+
 ### Prerequisites
 
 - [Deployed ERC-20 Base Contract](/contracts/modular-contracts/tutorials/deploy-erc20-core)