[Feature] Add sidecar init/run CLI wrappers (Phase B)

[djm81]

Feature Description

Add specfact sidecar init and specfact sidecar run CLI wrappers around the existing sidecar templates/scripts to make Phase B validation reproducible without manual shell steps.

Use Case

Primary Use Case: Brownfield Modernization

We validate OSS repos using the sidecar workflow (templates + harness + CrossHair). A CLI wrapper removes manual setup friction and makes dogfooding/validation repeatable.

Motivation

Current workflow requires manual sidecar-init.sh and run_sidecar.sh usage. A CLI wrapper improves DX, increases transparency for public beta users, and provides a stable surface for Phase B validation.

Proposed Solution

Add commands such as:

specfact sidecar init --repo /path/to/repo --bundle <name> --out /path/to/sidecar
specfact sidecar run --repo /path/to/repo --bundle <name> --out /path/to/sidecar --skip-specmatic

• Reuse existing templates under resources/templates/sidecar/
• Pass through environment variables and allow overrides
• Write outputs to .specfact/projects/<bundle>/reports/sidecar/

Alternative Solutions

Continue to use shell scripts only and document the workflow (current state).

Additional Context

Phase B validation relies on sidecar templates. The CLI wrapper would formalize it for users.

Impact

• User Impact: High
• Complexity: Medium
• Brownfield Relevance: High

Related Issues/PRs

• N/A

[djm81]

Related PR: #58

This PR improves the sidecar template infrastructure with code quality fixes and Django support enhancements. While it doesn't implement the CLI wrappers requested in this issue, it provides foundational improvements to the sidecar templates that will support the specfact sidecar init and specfact sidecar run commands:

• Code quality improvements to all sidecar template files
• Django-aware CrossHair wrapper (crosshair_django_wrapper.py)
• Django URL pattern extraction (django_url_extractor.py)
• Django form schema extraction (django_form_extractor.py)
• Contract population logic (populate_contracts.py)
• Improved sidecar-init.sh and run_sidecar.sh scripts

These improvements make the sidecar templates more robust and maintainable, which will facilitate the CLI wrapper implementation.