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>

claude.md

@@ -28,6 +28,14 @@ This is not a greenfield project. The architecture is proven. The Rust rewrite e
 ```
 rustybeds/
 ├── src/
+│   ├── brokers/
+│   │   ├── mod.rs              # Pool manager — spawn_r/w_broker_pool()
+│   │   ├── error.rs            # BrokerError type
+│   │   ├── payload.rs          # BrokerPayload — AMQP message body struct
+│   │   ├── r_broker.rs         # rBroker task — rec.read consume loop
+│   │   └── w_broker.rs         # wBroker task — rec.write consume loop
+│   ├── core/
+│   │   └── mod.rs              # NamasteCore trait — unified CRUD interface (stub)
 │   ├── config/
 │   │   ├── mod.rs              # load() + load_from() — layered TOML config
 │   │   └── structs.rs          # Typed config structs (serde Deserialize)
@@ -53,6 +61,7 @@ rustybeds/
 │   ├── example_rec.toml        # Canonical self-documenting REC template
 │   └── mst_logger_rec.toml     # Logger collection template (msLogs)
 ├── tests/
+│   ├── broker_pool_test.rs     # rBroker + wBroker pool integration tests
 │   ├── common/mod.rs           # Shared test helpers — load_test_config()
 │   └── fixtures/
 │       └── beds_test.toml      # Canonical test config fixture
@@ -65,15 +74,11 @@ rustybeds/
 ```
 src/
 ├── core/
-│   ├── trait.rs              # NamasteCore trait definition
-│   ├── factory.rs            # Template name → adapter dispatch
+│   ├── factory.rs            # Template name → NamasteCore dispatch
 │   └── meta.rs               # Request metadata parsing
-├── adapters/
-│   ├── mysql.rs              # gacPDO equivalent
-│   └── mongodb.rs            # gacMongoDB equivalent
-└── brokers/
-    ├── pool.rs               # Broker pool management
-    └── broker.rs             # Individual broker task
+└── adapters/
+    ├── mysql.rs              # gacPDO equivalent
+    └── mongodb.rs            # gacMongoDB equivalent
 ```
 
 ## Key Rust Mappings from PHP
@@ -91,17 +96,30 @@ src/
 
 ## NamasteCore Trait Interface
 
-The core CRUD interface. Every database adapter and every template must implement this:
+The core CRUD interface in `src/core/mod.rs`. Every template struct implements this:
 
 ```rust
 pub trait NamasteCore {
-    async fn create_record(&self, payload: &Payload) -> Result<Response, BEDSError>;
-    async fn fetch_records(&self, query: &Query) -> Result<Vec<Response>, BEDSError>;
-    async fn update_record(&self, payload: &Payload) -> Result<Response, BEDSError>;
-    async fn delete_record(&self, id: &str) -> Result<Response, BEDSError>;
+    fn template_id(&self) -> &'static str;
+    fn fetch(&self, params: HashMap<String, Value>) -> impl Future<Output = Result<Vec<HashMap<String, Value>>, String>> + Send;
+    fn write(&self, data: HashMap<String, Value>) -> impl Future<Output = Result<HashMap<String, Value>, String>> + Send;
+    fn update(&self, params: HashMap<String, Value>, data: HashMap<String, Value>) -> impl Future<Output = Result<u64, String>> + Send;
+    fn delete(&self, params: HashMap<String, Value>) -> impl Future<Output = Result<u64, String>> + Send;
 }
 ```
 
+Data in/out is always `HashMap<String, Value>` in user-facing field names. Templates own schema translation. Callers never provide primary keys on writes — the template generates a GUID.
+
+## BrokerPayload — AMQP Message Body
+
+The JSON body carried by all broker messages (`src/brokers/payload.rs`):
+
+```json
+{ "template": "usr", "data": { "first_name": "joe", "status": "active" } }
+```
+
+The AMQP `type` message property carries the operation (`fetch`, `write`, `update`, `delete`, `ping`, `shutdown`). The body carries the template identifier and data payload.
+
 ## Dependencies (Cargo.toml)
 
 ```toml