feat(clients): professional clients with tests, CI/CD, and examples

- Python: pyproject.toml, pytest suite (unit + integration), README, examples
- JavaScript: package.json, TypeScript definitions, node:test suite, README, examples
- Nim: integration tests, examples, README, improved nimble tasks
- Rust: fixed nodelay/localhost IPv6 bug, integration tests, examples, README
- Added GitHub Actions CI for all 4 clients against Docker server
- Added docker-compose.test.yml for local integration testing
- Added .gitignore for each client

clients/rust/examples/ping_test.rs

@@ -0,0 +1,11 @@
+use baradb::Client;
+
+fn main() {
+    let mut client = Client::connect("localhost", 9472).unwrap();
+    println!("Connected: {}", client.is_connected());
+    match client.ping() {
+        Ok(v) => println!("Ping: {}", v),
+        Err(e) => println!("Ping error: {}", e),
+    }
+    client.close();
+}