Function resolve_execution_account_address 

pub fn resolve_execution_account_address(
    private_key: Option<&str>,
    vault_address: Option<&str>,
    account_address: Option<&str>,
    environment: HyperliquidEnvironment,
) -> Result<Option<String>>

Resolves the execution account address used for REST queries and WebSocket subscriptions.

Precedence is explicit account address, explicit vault address, environment account address, environment vault address, then the signer address derived from the private key.

Errors

Returns an error if a selected vault address or private key is invalid.