Let docker deployments bind published ports to one host address

[xianjixiance]

Summary

The docker target publishes core and the web surfaces with a bare host:container mapping, so they listen on every interface of the host. On a machine with a public address that is an exposure the operator has to paper over with firewall rules outside qm, and a firewall rule in DOCKER-USER does not cover the IPv6 path through docker-proxy.

This adds bindAddress to the config: an IPv4 or IPv6 literal, overridable per invocation with QM_BIND_ADDRESS, that prefixes every published host port. The deployment-layer transport and the URLs qm up and qm outputs print follow the same address. Omitting it keeps today's behaviour.

Notes

• Validation accepts only IP literals (net.isIP), not hostnames, so a typo cannot silently publish on all interfaces.
• IPv6 literals are bracketed for docker's -p syntax and for the printed URLs.
• With sandbox.backend: "local" the sandboxes reach core through PUBLIC_API_URL, so the bind address has to stay routable from the sandbox daemon's containers; the docs say so, and loopback is not a candidate there.

Verification

• npm run typecheck and the CLI typecheck pass.
• cli/test/config.test.ts gains cases for valid IPv4 and IPv6 literals and for a hostname, an empty string, and a number being rejected; cli/test/docker-secrets.test.ts now asserts the published port carries the address prefix.
• eslint and prettier --check on the touched files pass.

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