Add rBroker + wBroker pool, BrokerPayload, NamasteCore trait stub

- src/brokers/: pool manager, r_broker (rec.read), w_broker (rec.write),
  BrokerPayload struct, BrokerError type
- src/core/: NamasteCore trait — fetch/write/update/delete interface, stubs
- IPL step 6: spawns rBroker + wBroker pools after exchange declaration
- tests/broker_pool_test.rs: integration tests for pool spawn (skip if broker down)
- BrokerPayload unit tests + doctest in payload.rs
- Added futures-lite, serde_json to Cargo.toml
- README.md, CLAUDE.md, wiki updated to reflect new structure and status

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

tests/broker_pool_test.rs

@@ -0,0 +1,98 @@
+//! # tests/broker_pool_test.rs — Broker Pool Integration Tests
+//!
+//! Integration tests for rBroker and wBroker pool spawn. These tests require
+//! a live RabbitMQ instance at the address in `tests/fixtures/beds_test.toml`.
+//! If the broker is unreachable, tests skip gracefully — they do not fail.
+//!
+//! Run with a live broker:
+//!   cargo test --test broker_pool_test
+//!
+//! **Author:** mks
+//! **Version:** 1.0
+//!
+//! ## History
+//! * `2026-04-05` - mks - original coding
+
+mod common;
+
+use std::sync::Arc;
+use rustybeds::brokers;
+use rustybeds::services::amqp::AmqpConnection;
+
+/// Attempts to connect to the test broker. Returns None if unreachable so
+/// tests can skip rather than fail when the broker isn't running.
+async fn try_connect(cfg: &rustybeds::config::BrokerServicesConfig) -> Option<Arc<lapin::Connection>> {
+    let uri = format!(
+        "amqp://{}:{}@{}:{}/{}",
+        cfg.app_server.user,
+        cfg.app_server.pass,
+        cfg.app_server.host,
+        cfg.app_server.port,
+        cfg.vhost,
+    );
+
+    match lapin::Connection::connect(&uri, lapin::ConnectionProperties::default()).await {
+        Ok(conn) => Some(Arc::new(conn)),
+        Err(_) => None,
+    }
+}
+
+#[tokio::test]
+async fn r_broker_pool_spawns_configured_instances() {
+    let cfg = common::load_test_config();
+
+    let conn = match try_connect(&cfg.broker_services).await {
+        Some(c) => c,
+        None => {
+            eprintln!("SKIP: RabbitMQ not available at test address");
+            return;
+        }
+    };
+
+    // declare exchange first — broker tasks expect it to exist
+    let amqp = AmqpConnection::connect(&cfg.broker_services).await
+        .expect("exchange declaration connection failed");
+    amqp.declare_exchange().await
+        .expect("exchange declaration failed");
+
+    let handles = brokers::spawn_r_broker_pool(Arc::clone(&conn), &cfg.broker_services)
+        .await
+        .expect("rBroker pool failed to start");
+
+    // fixture has r_broker = 2
+    assert_eq!(handles.len(), cfg.broker_services.app_server.instances.r_broker as usize);
+
+    // abort tasks cleanly — we're just testing spawn, not the consume loop
+    for h in handles {
+        h.abort();
+    }
+}
+
+#[tokio::test]
+async fn w_broker_pool_spawns_configured_instances() {
+    let cfg = common::load_test_config();
+
+    let conn = match try_connect(&cfg.broker_services).await {
+        Some(c) => c,
+        None => {
+            eprintln!("SKIP: RabbitMQ not available at test address");
+            return;
+        }
+    };
+
+    let amqp = AmqpConnection::connect(&cfg.broker_services).await
+        .expect("exchange declaration connection failed");
+    amqp.declare_exchange().await
+        .expect("exchange declaration failed");
+
+    let handles = brokers::spawn_w_broker_pool(Arc::clone(&conn), &cfg.broker_services)
+        .await
+        .expect("wBroker pool failed to start");
+
+    // fixture has w_broker = 2
+    assert_eq!(handles.len(), cfg.broker_services.app_server.instances.w_broker as usize);
+
+    for h in handles {
+        h.abort();
+    }
+}