feat: port el-ui vessels — rename crates→vessels, add El source + manifests

ui/vessels/el-services/src/lib.rs

@@ -0,0 +1,51 @@
+//! el-services — Service bindings for el-ui.
+//!
+//! Write once. Bind to any protocol. Change the binding in `el.toml`.
+//!
+//! ```toml
+//! [services.UserService]
+//! binding = "rest"
+//! base_url = "https://api.example.com"
+//! auth = "bearer"
+//! ```
+//!
+//! Switch `binding = "grpc"` and the same service code now speaks gRPC. No rewrite.
+
+pub mod binding;
+pub mod config;
+pub mod proxy;
+pub mod registry;
+
+pub use binding::{
+    direct::DirectBinding,
+    grpc::GrpcBinding,
+    rest::RestBinding,
+    websocket::WebSocketBinding,
+    Binding, BindingKind, ServiceRequest, ServiceResponse,
+};
+pub use config::{AuthConfig, ServiceConfig};
+pub use proxy::{ServiceMethod, ServiceProxy};
+pub use registry::ServiceRegistry;
+
+#[cfg(test)]
+mod tests;
+
+use thiserror::Error;
+
+#[derive(Debug, Error)]
+pub enum ServiceError {
+    #[error("service not found: {0}")]
+    NotFound(String),
+    #[error("binding error: {0}")]
+    Binding(String),
+    #[error("serialization error: {0}")]
+    Serialization(String),
+    #[error("transport error: {0}")]
+    Transport(String),
+    #[error("auth error: {0}")]
+    Auth(String),
+    #[error("method not found: {method} on service {service}")]
+    MethodNotFound { service: String, method: String },
+}
+
+pub type ServiceResult<T> = Result<T, ServiceError>;