Merge main: resolve nav conflicts with Zama and ecosystem adapters

- useNavigationTree: keep useState lastEcosystem + effect (hydration); set
  zama from /confidential-contracts and midnight from /contracts-compact; add
  zama and ecosystem-adapters to shared-path switch.
- docs-layout: same state pattern; merge zamaUrls with ecosystem-adapters tab
  attribution and Ethereum/Midnight conditional urls.

Author: pasevin

content/relayer/1.4.x/guides/index.mdx

@@ -6,20 +6,4 @@ title: Guides
 
 Step-by-step guides for integrating with OpenZeppelin Relayer services and implementing common patterns for blockchain applications.
 
-## Available Guides
-
-### Stellar Channels Guide
-
-A comprehensive guide to using the OpenZeppelin Stellar Channels Service - a managed infrastructure for submitting Stellar Soroban transactions with automatic parallel processing and fee management.
-
-[Read the Stellar Channels Guide →](./stellar-channels-guide.mdx)
-
-### Stellar Sponsored Transactions Guide
-
-A complete guide to implementing gasless transactions on Stellar, allowing users to pay fees in tokens instead of XLM. Learn how to configure trustlines, use the quote/build/send API flow, and handle fee conversions.
-
-[Read the Stellar Sponsored Transactions Guide →](./stellar-sponsored-transactions-guide.mdx)
-
-### Stellar x402 Facilitator Guide
-
-[Read the Stellar x402 Facilitator Guide →](./stellar-x402-facilitator-guide.mdx)
+Browse the available guides for your network in the sidebar.