feat(wfe-valkey): add Valkey provider for locks, queues, and lifecycle events

ValkeyLockProvider: SET NX EX for acquisition, Lua script for safe release.
ValkeyQueueProvider: LPUSH/RPOP for FIFO queues.
ValkeyLifecyclePublisher: PUBLISH to per-instance and global channels.

Connections obtained once during construction (no per-operation TCP handshakes).

wfe-valkey/Cargo.toml

@@ -0,0 +1,25 @@
+[package]
+name = "wfe-valkey"
+version.workspace = true
+edition.workspace = true
+license.workspace = true
+description = "Valkey/Redis provider for distributed locking, queues, and lifecycle events in WFE"
+
+[dependencies]
+wfe-core = { workspace = true }
+redis = { workspace = true }
+tokio = { workspace = true }
+serde = { workspace = true }
+serde_json = { workspace = true }
+async-trait = { workspace = true }
+uuid = { workspace = true }
+thiserror = { workspace = true }
+tracing = { workspace = true }
+
+[dev-dependencies]
+wfe-core = { workspace = true, features = ["test-support"] }
+pretty_assertions = { workspace = true }
+rstest = { workspace = true }
+tokio = { workspace = true, features = ["test-util"] }
+tokio-stream = { workspace = true }
+uuid = { workspace = true }