Add screenshot and embed in README

chore(client): bump version to 0.3.6

docs(client): update skill title and add broker repo link

Update LICENSE copyright holder/year

Add SECURITY.md security policy

Add Apache 2.0 LICENSE file

Add broker URL examples to registration docs

Update README: Cloudflare setup and diagram

Add account_id to broker wrangler.toml

Load account ID from env or wrangler.toml

Update package.json

Add example wrangler.toml for broker

Ignore local wrangler config

Remove broker-side signature verification

Add self-hosted broker docs and queue design