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/nim/examples/basic.nim

@@ -0,0 +1,96 @@
+## BaraDB Nim Client — Basic Examples
+## Make sure BaraDB is running on localhost:9472
+
+import std/asyncdispatch
+import std/strutils
+import baradb/client
+
+proc exampleConnection() {.async.} =
+  echo "=== Connection ==="
+  let client = newClient()
+  await client.connect()
+  echo "Connected: ", client.isConnected
+  echo "Ping: ", await client.ping()
+  client.close()
+  echo "Connected after close: ", client.isConnected
+  echo ""
+
+proc exampleSimpleQuery() {.async.} =
+  echo "=== Simple Query ==="
+  let client = newClient()
+  await client.connect()
+  let result = await client.query("SELECT 42 as answer, 'BaraDB' as db")
+  echo "Columns: ", result.columns
+  echo "Row count: ", result.rowCount
+  for row in result.rows:
+    echo "  ", row.join(", ")
+  client.close()
+  echo ""
+
+proc exampleParameterizedQuery() {.async.} =
+  echo "=== Parameterized Query ==="
+  let client = newClient()
+  await client.connect()
+  let result = await client.query(
+    "SELECT $1 as num, $2 as txt",
+    @[
+      WireValue(kind: fkInt64, int64Val: 123),
+      WireValue(kind: fkString, strVal: "hello world"),
+    ]
+  )
+  for row in result.rows:
+    echo "  ", row.join(", ")
+  client.close()
+  echo ""
+
+proc exampleQueryBuilder() {.async.} =
+  echo "=== Query Builder ==="
+  let client = newClient()
+  await client.connect()
+  let sql = newQueryBuilder(client)
+    .select("id", "name")
+    .from("users")
+    .where("active = true")
+    .orderBy("name", "ASC")
+    .limit(5)
+    .build()
+  echo "Generated SQL: ", sql
+  client.close()
+  echo ""
+
+proc exampleDdlDml() {.async.} =
+  echo "=== DDL & DML ==="
+  let client = newClient()
+  await client.connect()
+
+  try:
+    discard await client.exec("DROP TABLE IF EXISTS demo_products")
+  except:
+    discard
+
+  discard await client.exec("CREATE TABLE demo_products (id INT PRIMARY KEY, name STRING, price FLOAT)")
+  let affected = await client.exec("INSERT INTO demo_products (id, name, price) VALUES (1, 'Widget', 9.99)")
+  echo "Insert affected rows: ", affected
+
+  let result = await client.query("SELECT * FROM demo_products")
+  echo "Select returned ", result.rowCount, " row(s)"
+  for row in result.rows:
+    echo "  ", row.join(", ")
+
+  discard await client.exec("DROP TABLE demo_products")
+  echo "Table dropped"
+  client.close()
+  echo ""
+
+proc main() {.async.} =
+  echo "BaraDB Nim Client Examples"
+  echo "Make sure BaraDB is running on localhost:9472"
+  echo ""
+
+  await exampleConnection()
+  await exampleSimpleQuery()
+  await exampleParameterizedQuery()
+  await exampleQueryBuilder()
+  await exampleDdlDml()
+
+waitFor main()