Automated Bootstrapping for Derived Catalogs

## Description
Currently, the Gemara spec supports creating a catalog based on another (inheritance/selection - `extend`/`import`), but the process is manual for creation. Based on the ORBIT Working Group discussion on 2026-05-07, there seems to be a growing need to create layered catalogs on top of the OSPS Baseline.

We need a bootstrapping mechanism in the SDK that supports a user to programmatically generate a "child" catalog from a "parent" catalog.

## Proposed Workflow

- [ ] User runs a command like `grcli init --from [Parent-Catalog-URI]`.
- [ ] User selects whether they want to inherit all controls or a specific subset.
- [ ] The tool generates a new Gemara catalog file with metadata already populated.

### Success Criteria

- The bootstrapping logic ensures the parent URI is reachable and valid Gemara.
- The metadata is automatically linked tso the child catalog knows which version of the parent it was created from.
- Provide a boilerplate structure for the "new" controls to be added.

## Context

- Specifically addressed the friction point of keeping the Baseline clean while allowing specialized extensions.
- This functionality would be supported the Gemara Hub initiative by making it easier to publish derivative works.