Add MCP server to AST tool

Integrates the MCP server functionality into the AST tool binary. This
allows the tool to act as a server for LLM integration, enabling
communication over stdio. The server can list available bindings and
execute scripts.

Cargo.toml

@@ -10,6 +10,9 @@ clap = { version = "4.5", features = ["derive"] }
 chrono = "0.4"
 regex = "1.10"
 fastrand = "2.3"
+rmcp = { version = "1.2", features = ["server", "transport-io"] }
+tokio = { version = "1", features = ["rt", "io-std", "macros"] }
+serde = { version = "1", features = ["derive"] }
 
 [dev-dependencies]
 insta = { version = "1.39", features = ["yaml"] }