Pr/basic websocket

[alexeyslynko]

Summary

Adds a basic WebSocket endpoint to @type-r/endpoints.

The implementation provides collection live updates through subscribe() / unsubscribe() and keeps REST operations separate. Multiple collections using the same WebSocket URL, constructor, and protocols share one WebSocket connection, while each collection still sends its own subscribe/unsubscribe messages.

Included

• websocketIO(url, options?) for basic collection live updates
• restfulWebsocketIO(url, websocketUrl, options?) combining restfulIO CRUD/list with WebSocket live updates
• shared WebSocket connection registry
• support for updated / removed live update messages
• compact message envelopes: { updated } and { removed }
• documentation for both endpoint helpers

Basic Options

WebSocketEndpointOptions intentionally stays small:

• WebSocket
• protocols
• match
• subscribeMessage
• unsubscribeMessage

The basic endpoint uses JSON messages only. It does not include reconnect, heartbeat, subscribe acknowledgements, cursors, replay, resync, or custom message encoding.

Testing

• rollup --config in endpoints passed
• Full tsc was not runnable in the local workspace with the current TypeScript 6 setup because the old branch has existing unrelated type/config incompatibilities