fix(clients): repair Python & Rust tests, add container test orchestration

- Python: fix wire protocol test method names (bool_val -> bool, etc.)
- Python: make integration tests and example fully async with pytest-asyncio
- Rust: add tokio dev-dependency and convert integration tests to async/await
- Rust: update ping_test example to async
- Nim: remove committed ELF build artifact
- Docker: add BARADB_HOST/BARADB_PORT env vars to test containers
- Docker: fix docker-compose.test.yml usage (remove --abort-on-container-exit)
- Add scripts/test-clients.sh for sequential client test runs
- Remove docker-compose.test.yml from .gitignore so it is tracked
- Fix repository URLs in Python and Rust READMEs

clients/rust/examples/ping_test.rs

@@ -1,11 +1,12 @@
 use baradb::Client;
 
-fn main() {
-    let mut client = Client::connect("localhost", 9472).unwrap();
+#[tokio::main]
+async fn main() {
+    let mut client = Client::connect("localhost", 9472).await.unwrap();
     println!("Connected: {}", client.is_connected());
-    match client.ping() {
+    match client.ping().await {
         Ok(v) => println!("Ping: {}", v),
         Err(e) => println!("Ping error: {}", e),
     }
-    client.close();
+    client.close().await;
 }