Use explicit type exports and add ClientConfig default test

- Replace `pub use types::*` with explicit named exports for a
  cleaner public API surface
- Add test asserting ClientConfig::default() values since they
  are part of the public API contract

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: dkijania

src/lib.rs

@@ -35,4 +35,7 @@ mod types;
 pub use client::{ClientConfig, MinaClient};
 pub use currency::Currency;
 pub use error::{Error, Result};
-pub use types::*;
+pub use types::{
+    AccountBalance, AccountData, BlockInfo, DaemonStatus, PeerInfo, PooledUserCommand,
+    SendDelegationResult, SendPaymentResult, SyncStatus,
+};

tests/client_tests.rs

@@ -5,6 +5,15 @@ use wiremock::{Mock, MockServer, ResponseTemplate};
 
 use mina_sdk::*;
 
+#[test]
+fn test_client_config_defaults() {
+    let config = ClientConfig::default();
+    assert_eq!(config.graphql_uri, "http://127.0.0.1:3085/graphql");
+    assert_eq!(config.retries, 3);
+    assert_eq!(config.retry_delay, Duration::from_secs(5));
+    assert_eq!(config.timeout, Duration::from_secs(30));
+}
+
 fn test_config(uri: &str) -> ClientConfig {
     ClientConfig {
         graphql_uri: uri.to_string(),