Add DeltaChat Channel

The adapter drives the @deltachat/stdio-rpc-server JSON-RPC subprocess directly — pure Node.js against the DeltaChat core library. Messages are delivered over email with Autocrypt/OpenPGP encryption.

Install

1. Copy the adapter and its registration test

Fetch the channels branch from the configured remote that carries it, then overwrite the skill-owned files with the canonical registry copies:

src/channels/deltachat.ts
src/channels/deltachat-registration.test.ts

2. Append the self-registration import

Append to src/channels/index.ts (skip if already present):