fix: improve error handling in ephemeral validator (#189)

Co-authored-by: Gabriele Picco <piccogabriele@gmail.com>
Co-authored-by: Danilo Guanabara <danilo@magicblock.gg>

crates/bolt-cli/src/ephemeral_validator.rs

@@ -39,7 +39,7 @@ impl EphemeralValidator {
             &temp_file,
             include_str!("templates/ephemeral-validator.toml"),
         )
-        .expect("Failed to write ephemeral validator config");
+        .map_err(|e| anyhow::anyhow!("Failed to write ephemeral validator config: {}", e))?;
         tokio::process::Command::new("ephemeral-validator")
             .arg(temp_file)
             .spawn()