test: add comprehensive Tower integration tests

Add extensive test coverage for Tower service integration:

- Basic Tower service tests for both Cloud and Enterprise clients
  - All HTTP methods (GET, POST, PUT, PATCH, DELETE)
  - Oneshot and multiple request patterns
  - Error handling and validation

- Tower middleware composition tests
  - Timeout middleware with configurable durations
  - Rate limiting with token bucket
  - Buffer layer for concurrent request handling
  - Custom middleware for request counting
  - Full middleware stack composition

- Add tower dev dependency for middleware features
- Re-export tower_support module from lib.rs when tower-integration feature enabled

Tests demonstrate CloudClient and EnterpriseClient work correctly with
Tower's middleware ecosystem for production patterns like timeouts,
rate limiting, and buffering.

Author: joshrotenberg

Cargo.lock

@@ -38,3 +38,4 @@ wiremock = { workspace = true }
 tokio = { workspace = true, features = ["rt", "macros", "test-util"] }
 pretty_assertions = { workspace = true }
 serial_test = { workspace = true }
+tower = { version = "0.5", features = ["timeout", "limit", "retry", "buffer"] }

crates/redis-cloud/Cargo.toml

@@ -284,6 +284,10 @@ mod lib_tests;
 // Re-export client types
 pub use client::{CloudClient, CloudClientBuilder};
 
+// Re-export Tower integration when feature is enabled
+#[cfg(feature = "tower-integration")]
+pub use client::tower_support;
+
 // Types module for shared models
 pub mod types;