feat(unstable): initial unstable nes implementation

AGENTS.md

@@ -19,9 +19,7 @@ All paths in the protocol should be absolute
 
 - Add constants for the method names
 - Add variants to {Agent|Client}{Request|Response} enums
-- Add the methods to the Client/Agent impl of {Agent|Client}SideConnection in src/acp.rs
 - Handle the new method in the `Side::decode_request`/`Side::decode_notification` implementation
-- Handle the new request in the blanket impl of MessageHandler<{Agent|Client}Side>
 - Add the method to markdown_generator.rs SideDocs functions
 - Run `npm run generate` and fix any issues that appear
 - Run `npm run check`

Cargo.toml

@@ -19,6 +19,7 @@ unstable = [
     "unstable_cancel_request",
     "unstable_elicitation",
     "unstable_logout",
+    "unstable_nes",
     "unstable_session_additional_directories",
     "unstable_session_fork",
     "unstable_session_model",
@@ -32,6 +33,7 @@ unstable_auth_methods = []
 unstable_cancel_request = []
 unstable_elicitation = []
 unstable_logout = []
+unstable_nes = []
 unstable_session_additional_directories = []
 unstable_session_fork = []
 unstable_session_model = []