Add production Docker Compose bundle

[tlongwell-block]

Summary

Adds a first-party single-node/VPS Docker Compose deployment bundle under deploy/compose/:

• production base stack: Buzz relay + Postgres + Redis + Typesense + MinIO + MinIO bucket init + git data volume
• Caddy TLS override for public VPS installs
• dev override for local admin ports/tools without polluting the production base
• .env.example with stable secret placeholders and correct Buzz env names
• run.sh lifecycle wrapper around docker compose up -d --wait, config rendering, logs, upgrade, and backup reminders
• README with current caveats around public image and auto-migration dependencies

Validation

• bash -n deploy/compose/run.sh
• placeholder guard rejects untouched .env.example
• rendered configs successfully:
  • ./deploy/compose/run.sh config
  • BUZZ_COMPOSE_TLS=true ./deploy/compose/run.sh config
  • BUZZ_COMPOSE_DEV=true ./deploy/compose/run.sh config
• verified TLS override removes direct relay port publishing and exposes only Caddy 80/443
• git diff --check
• pre-commit hook passed formatting/fix hooks during commit

Not yet end-to-end started: ghcr.io/block/buzz is still waiting on the public image PR and fresh-DB success depends on the automatic migrations PR.

Notes

This intentionally does not touch the root docker-compose.yml; that file remains local dev infra. We can decide separately whether to migrate root dev compose onto deploy/compose/compose.dev.yml after the deployment PRs stabilize.