Update llms summaries for Base Account and Cookbook

Adds Advanced Authentication guide and Cross-Chain Apps guide to llms.txt and llms-full.txt to reflect new docs added in PR #408.

Author: cursoragent

docs/base-account/llms-full.txt

@@ -32,6 +32,7 @@ const { status } = await getPaymentStatus({ id })
 
 ### Guides
 - [Authenticate Users](https://docs.base.org/base-account/guides/authenticate-users.md) — SIWE + ERC‑6492
+- [Advanced Authentication Patterns](https://docs.base.org/base-account/guides/advanced-authentication.md) — MFA, TOTP, sessions, cross‑device sync
 - [Accept Payments](https://docs.base.org/base-account/guides/accept-payments.md) — Base Pay
 - [Batch Transactions](https://docs.base.org/base-account/improve-ux/batch-transactions.md) — Multi‑call
 - [Paymasters](https://docs.base.org/base-account/improve-ux/sponsor-gas/paymasters.md) — Sponsor gas

docs/base-account/llms.txt

@@ -13,6 +13,7 @@
 
 ## Guides
 - [Authenticate Users](https://docs.base.org/base-account/guides/authenticate-users.md) — SIWE with ERC‑6492 signatures
+- [Advanced Authentication Patterns](https://docs.base.org/base-account/guides/advanced-authentication.md) — MFA, TOTP, sessions, cross‑device sync
 - [Accept Payments](https://docs.base.org/base-account/guides/accept-payments.md) — One‑tap USDC payments with Base Pay
 
 ## Framework Integrations

docs/cookbook/llms-full.txt

@@ -14,6 +14,7 @@
 ### Use Cases
 - [Onboard Any User](https://docs.base.org/cookbook/onboard-any-user.md) — UX patterns to remove friction
 - [Accept Crypto Payments](https://docs.base.org/cookbook/accept-crypto-payments.md) — Payments flows
+- [Build Cross-Chain Apps](https://docs.base.org/cookbook/build-cross-chain-apps.md) — Hub-and-spoke, bridges, cross-chain messaging, unified UX
 - [Launch AI Agents](https://docs.base.org/cookbook/launch-ai-agents.md) — Agent patterns and tooling
 - [Launch Tokens](https://docs.base.org/cookbook/launch-tokens.md) — Responsible token launch
 - [Deploy a Chain](https://docs.base.org/cookbook/deploy-a-chain.md) — OP Stack deployment

docs/cookbook/llms.txt

@@ -7,6 +7,7 @@
 ## Use Cases
 - [Onboard Any User](https://docs.base.org/cookbook/onboard-any-user.md) — Reduce friction and improve conversion
 - [Accept Crypto Payments](https://docs.base.org/cookbook/accept-crypto-payments.md) — Add payments flows
+- [Build Cross-Chain Apps](https://docs.base.org/cookbook/build-cross-chain-apps.md) — Architecture, bridges, messaging, UX patterns
 - [Launch AI Agents](https://docs.base.org/cookbook/launch-ai-agents.md) — Ship messaging agents
 - [Launch Tokens](https://docs.base.org/cookbook/launch-tokens.md) — Responsible token launch patterns
 - [Deploy a Chain](https://docs.base.org/cookbook/deploy-a-chain.md) — OP Stack deployment guide