feat(release): add customer install bundle

[simonjcarr]

Summary

• add a CT-CVE customer bundle with docker-compose.yml, .env.example, start.sh, upgrade.sh, and bundled README
• bootstrap .env on first start, generate the database password, and wait for post-migration health
• package versioned and stable release zip artifacts with SHA-256 files after publishing the GHCR image
• add CI coverage for bundle packaging, first start, and local-zip upgrade behavior

Validation

• bash -n deploy/customer-bundle/start.sh deploy/customer-bundle/upgrade.sh deploy/scripts/package-customer-bundle.sh deploy/scripts/test-customer-bundle.sh
• bash deploy/scripts/test-customer-bundle.sh
• go test ./...
• docker compose config against the customer compose file with generated env values