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/basic.rs

@@ -0,0 +1,127 @@
+// BaraDB Rust Client — Basic Examples
+// Make sure BaraDB is running on localhost:9472.
+
+use baradb::{Client, QueryBuilder, WireValue};
+
+fn example_connection() -> Result<(), Box<dyn std::error::Error>> {
+    println!("=== Connection ===");
+    let mut client = Client::connect("127.0.0.1", 9472)?;
+    println!("Connected: {}", client.is_connected());
+    println!("Ping: {}", client.ping()?);
+    client.close();
+    println!("Connected after close: {}", client.is_connected());
+    println!();
+    Ok(())
+}
+
+fn example_simple_query() -> Result<(), Box<dyn std::error::Error>> {
+    println!("=== Simple Query ===");
+    let mut client = Client::connect("127.0.0.1", 9472)?;
+    let result = client.query("SELECT 42 as answer, 'BaraDB' as db")?;
+    println!("Columns: {:?}", result.columns());
+    println!("Row count: {}", result.row_count());
+    for row in result.rows() {
+        println!("  {:?}", row);
+    }
+    client.close();
+    println!();
+    Ok(())
+}
+
+fn example_parameterized_query() -> Result<(), Box<dyn std::error::Error>> {
+    println!("=== Parameterized Query ===");
+    let mut client = Client::connect("127.0.0.1", 9472)?;
+    let result = client.query_params(
+        "SELECT $1 as num, $2 as txt, $3 as flag",
+        &[
+            WireValue::Int64(123),
+            WireValue::String("hello world".to_string()),
+            WireValue::Bool(true),
+        ],
+    )?;
+    for row in result.rows() {
+        println!("  {:?}", row);
+    }
+    client.close();
+    println!();
+    Ok(())
+}
+
+fn example_query_builder() -> Result<(), Box<dyn std::error::Error>> {
+    println!("=== Query Builder ===");
+    let mut client = Client::connect("127.0.0.1", 9472)?;
+    let sql = QueryBuilder::new(&mut client)
+        .select(&["id", "name"])
+        .from("users")
+        .where_clause("active = true")
+        .order_by("name", "ASC")
+        .limit(5)
+        .build();
+    println!("Generated SQL: {}", sql);
+    client.close();
+    println!();
+    Ok(())
+}
+
+fn example_vector() -> Result<(), Box<dyn std::error::Error>> {
+    println!("=== Vector Value ===");
+    let mut client = Client::connect("127.0.0.1", 9472)?;
+    let result = client.query_params(
+        "SELECT $1 as embedding",
+        &[WireValue::Vector(vec![0.1, 0.2, 0.3, 0.4])],
+    )?;
+    for row in result.rows() {
+        println!("  {:?}", row);
+    }
+    client.close();
+    println!();
+    Ok(())
+}
+
+fn example_ddl_dml() -> Result<(), Box<dyn std::error::Error>> {
+    println!("=== DDL & DML ===");
+    let mut client = Client::connect("127.0.0.1", 9472)?;
+
+    let _ = client.execute("DROP TABLE IF EXISTS demo_products");
+
+    client.execute(
+        "CREATE TABLE demo_products (id INT PRIMARY KEY, name STRING, price FLOAT)",
+    )?;
+    let affected = client.execute(
+        "INSERT INTO demo_products (id, name, price) VALUES (1, 'Widget', 9.99)",
+    )?;
+    println!("Insert affected rows: {}", affected);
+
+    let result = client.query("SELECT * FROM demo_products")?;
+    println!("Select returned {} row(s)", result.row_count());
+    for row in result.rows() {
+        println!("  {:?}", row);
+    }
+
+    client.execute("DROP TABLE demo_products")?;
+    println!("Table dropped");
+    client.close();
+    println!();
+    Ok(())
+}
+
+fn main() {
+    println!("BaraDB Rust Client Examples");
+    println!("Make sure BaraDB is running on localhost:9472");
+    println!();
+
+    let examples: Vec<fn() -> Result<(), Box<dyn std::error::Error>>> = vec![
+        example_connection,
+        example_simple_query,
+        example_parameterized_query,
+        example_query_builder,
+        example_vector,
+        example_ddl_dml,
+    ];
+
+    for example in examples {
+        if let Err(e) = example() {
+            eprintln!("ERROR: {}", e);
+        }
+    }
+}