feat(config): integrate etcd for service discovery and config management

- Add etcd-client dependency for distributed configuration storage
- Implement EtcdConfig with priority: etcd > environment variables > defaults
- Add ServiceRegistry for service registration with lease keep-alive
- Integrate etcd-based service discovery for appks gRPC connections
- Add service watcher for real-time service instance updates
- Migrate Redis configuration from single URL to cluster node list
- Update Dockerfile with default IMKS_HOST and IMKS_PORT environment variables
- Add etcd bootstrap configuration through environment variables
- Implement Redis cluster URL building with optional authentication

Cargo.toml

@@ -14,15 +14,15 @@ name = "imks"
 
 
 [dependencies]
-tonic = { version = "0.14.6", features = ["tls-ring"] }
-prost = "0.14.3"
+tonic = { version = "0.14", features = ["tls-ring"] }
+prost = "0.14"
 prost-types = "0.14"
-tonic-build = "0.14.6"
-tonic-health = "0.14.6"
-tonic-prost = "0.14.6"
-tokio = { version = "1.52.3", features = ["full"] }
-actix-web = { version = "4.13.0", features = [] }
-actix-ws = { version = "0.4.0", features = [] }
+tonic-build = "0.14"
+tonic-health = "0.14"
+tonic-prost = "0.14"
+tokio = { version = "1", features = ["full"] }
+actix-web = { version = "4", features = [] }
+actix-ws = { version = "0.4", features = [] }
 actix-rt = "2"
 serde = { version = "1", features = ["derive"] }
 serde_json = { version = "1" }
@@ -34,6 +34,8 @@ rand = "0.9"
 wtransport = "0.7"
 dashmap = "6"
 thiserror = "2"
+etcd-client = { version = "0.18", features = ["tls"] }
+tokio-stream = { version = "0.1", features = ["sync"] }
 async-trait = "0.1"
 tracing = "0.1"
 tracing-subscriber = { version = "0.3", features = ["env-filter", "json", "fmt", "registry"] }
@@ -52,5 +54,5 @@ arc-swap = "1"
 
 
 [build-dependencies]
-tonic-prost-build = "0.14.6"
-walkdir = "2.5.0"
+tonic-prost-build = "0.14"
+walkdir = "2.5"