Add Google Chat Channel

Adds Google Chat support via the Chat SDK bridge.

Install

NanoClaw doesn't ship channels in trunk. This skill copies the Google Chat adapter in from the channels branch.

Pre-flight (idempotent)

Skip to Credentials if all of these are already in place:

• src/channels/gchat.ts exists
• src/channels/index.ts contains import './gchat.js';
• @chat-adapter/gchat is listed in package.json dependencies

Otherwise continue. Every step below is safe to re-run.

1. Fetch the channels branch