feat: vendor ag-ui-core and ag-ui-server crates

  Move AG-UI protocol crates into the repository to fix release-plz
  dependency resolution issues. These crates enable frontend connectivity
  for agent mode.

Author: Alex Holmberg

Cargo.toml

@@ -85,8 +85,8 @@ futures-util = "0.3"
 rig-core = { version = "0.28", features = ["derive", "image"] }
 
 # AG-UI Protocol - enables frontend connectivity for agent mode
-ag-ui-core = { path = "../ag-ui-sdk/crates/ag-ui-core" }
-ag-ui-server = { path = "../ag-ui-sdk/crates/ag-ui-server" }
+ag-ui-core = { path = "crates/ag-ui-core" }
+ag-ui-server = { path = "crates/ag-ui-server" }
 axum = { version = "0.8", features = ["ws"] }
 tower-http = { version = "0.6", features = ["cors"] }
 tokio-stream = { version = "0.1", features = ["sync"] }

crates/ag-ui-core/Cargo.toml

@@ -0,0 +1,16 @@
+[package]
+name = "ag-ui-core"
+version = "0.1.0"
+edition = "2024"
+rust-version = "1.88"
+license = "MIT"
+description = "Core type library for AG-UI protocol - Syncable SDK"
+readme = "README.md"
+
+[dependencies]
+thiserror = "2"
+serde = { version = "1", features = ["derive"] }
+serde_json = "1"
+json-patch = "3"
+jsonptr = "0.6"
+uuid = { version = "1", features = ["v4", "serde"] }

crates/ag-ui-core/src/error.rs

@@ -0,0 +1,30 @@
+//! Error types for AG-UI core operations.
+
+use thiserror::Error;
+
+/// Errors that can occur in AG-UI core operations.
+#[derive(Debug, Error)]
+pub enum AgUiError {
+    /// Error during JSON serialization/deserialization
+    #[error("Serialization error: {0}")]
+    Serialization(#[from] serde_json::Error),
+
+    /// Validation error for event or message data
+    #[error("Validation error: {0}")]
+    Validation(String),
+
+    /// Invalid event format or structure
+    #[error("Invalid event: {0}")]
+    InvalidEvent(String),
+
+    /// Invalid message format or content
+    #[error("Invalid message: {0}")]
+    InvalidMessage(String),
+
+    /// State operation error
+    #[error("State error: {0}")]
+    State(String),
+}
+
+/// Result type alias using AgUiError
+pub type Result<T> = std::result::Result<T, AgUiError>;