[Copilot]

Unit Tests (3) failed when XDC network detection could not reach the configured RPC. Verification used only the first endpoint, so it had no fallback.

• RPC configuration: Add a second public XDC endpoint to the default configuration.
• Verification: Use an ethers FallbackProvider when multiple RPCs are configured, with chain ID 50 set on each provider.

new ethers.providers.FallbackProvider(
  rpcs.map(endpoint => new ethers.providers.JsonRpcProvider(endpoint, chainId)),
  1
)

• Coverage: Add a network-free test confirming both default XDC endpoints are used.