Promote service modules to services/ directory; add AmqpConnection + async IPL

- Flat src/amqp.rs, src/mongo.rs, src/mariadb.rs promoted to src/services/{amqp,mongo,mariadb}/
- services/amqp/connection.rs: AmqpConnection struct with connect() and declare_exchange()
- services/amqp/error.rs: AmqpError type (thiserror, wraps lapin::Error)
- ipl() made async; #[tokio::main] added to main()
- IPL step 3b: authenticate to RabbitMQ + declare beds.events topic exchange (durable)
- Added lapin = "2" and tokio = { version = "1", features = ["full"] } to Cargo.toml
- 12 unit tests pass
- Docs: README, CLAUDE.md, wiki/04-ipl.md, wiki/06-queue-topology.md updated

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

claude.md

@@ -29,26 +29,33 @@ This is not a greenfield project. The architecture is proven. The Rust rewrite e
 rustybeds/
 ├── src/
 │   ├── config/
-│   │   ├── mod.rs            # load() + load_from() — layered TOML config
-│   │   └── structs.rs        # Typed config structs (serde Deserialize)
-│   ├── amqp.rs               # RabbitMQ transport — validate(), future channel/queue ops
-│   ├── mariadb.rs            # MariaDB transport — validate_all(), master/secondary pattern
-│   ├── mongo.rs              # MongoDB transport — validate_all(), future adapter ops
-│   ├── lib.rs                # Public API surface for integration test harness
-│   ├── logging.rs            # tracing + journald + console mirror init
-│   └── main.rs               # ipl() sequence + main()
+│   │   ├── mod.rs              # load() + load_from() — layered TOML config
+│   │   └── structs.rs          # Typed config structs (serde Deserialize)
+│   ├── services/
+│   │   ├── mod.rs              # Groups external service transport modules
+│   │   ├── amqp/
+│   │   │   ├── mod.rs          # validate() — TCP reachability pre-flight
+│   │   │   ├── connection.rs   # AmqpConnection — auth + exchange declare
+│   │   │   └── error.rs        # AmqpError type
+│   │   ├── mongo/
+│   │   │   └── mod.rs          # validate_all() — TCP reachability
+│   │   └── mariadb/
+│   │       └── mod.rs          # validate_all() — master/secondary pattern
+│   ├── lib.rs                  # Public API surface for integration test harness
+│   ├── logging.rs              # tracing + journald + console mirror init
+│   └── main.rs                 # async ipl() sequence + #[tokio::main] main()
 ├── config/
-│   ├── beds.toml             # Base config — checked in, no credentials
-│   ├── env_dev.toml          # Dev overrides — gitignored
-│   ├── env_qa.toml           # QA overrides — gitignored
-│   └── env_prod.toml         # Prod overrides — gitignored
+│   ├── beds.toml               # Base config — checked in, no credentials
+│   ├── env_dev.toml            # Dev overrides — gitignored
+│   ├── env_qa.toml             # QA overrides — gitignored
+│   └── env_prod.toml           # Prod overrides — gitignored
 ├── templates/
-│   ├── example_rec.toml      # Canonical self-documenting REC template
-│   └── mst_logger_rec.toml   # Logger collection template (msLogs)
+│   ├── example_rec.toml        # Canonical self-documenting REC template
+│   └── mst_logger_rec.toml     # Logger collection template (msLogs)
 ├── tests/
-│   ├── common/mod.rs         # Shared test helpers — load_test_config()
+│   ├── common/mod.rs           # Shared test helpers — load_test_config()
 │   └── fixtures/
-│       └── beds_test.toml    # Canonical test config fixture
+│       └── beds_test.toml      # Canonical test config fixture
 ├── Cargo.toml
 └── CLAUDE.md
 ```