Add monorepo support (multiple projects in one repo)

[herakles-dev]

Currently the pipeline assumes one project = one directory. But many teams use monorepos with multiple services.

Desired behavior:

• /opensource fork my-monorepo should detect if the project has multiple services (e.g., packages/, services/, apps/ directories)
• The forker should handle shared config at the root AND per-service config
• The packager should generate a CLAUDE.md that describes the monorepo structure

Questions to solve:

• Should the sanitizer scan the entire monorepo, or allow scoping to specific packages?
• How should .env.example work — one per service or one at the root?

Would love ideas and PRs from anyone working with monorepos.