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/tests/lock.rs

@@ -0,0 +1,8 @@
+use wfe_core::lock_suite;
+
+async fn make_provider() -> wfe_valkey::ValkeyLockProvider {
+    let prefix = format!("wfe_test_{}", uuid::Uuid::new_v4().simple());
+    wfe_valkey::ValkeyLockProvider::new("redis://localhost:6379", &prefix).await.unwrap()
+}
+
+lock_suite!(make_provider);