feat: add CLI output controls

[APonder-Dev]

Summary

This pull request introduces configurable CLI controls and operational workflow improvements for SentinelAudit v0.2.0.

SentinelAudit now supports user-controlled report generation workflows, custom output handling, and improved execution flexibility through a dedicated command-line interface layer.

Major Changes

Added CLI Module

• Added sentinel_audit/cli.py
• Added centralized argument parsing
• Improved execution workflow organization

Added CLI Features

• Added --format support
• Added --output support
• Added --version support
• Added configurable report generation workflows

Reporting Improvements

• Added JSON-only report generation
• Added Markdown-only report generation
• Added simultaneous multi-format report generation
• Added custom output path handling

Testing Improvements

• Added CLI parser unit tests
• Expanded automated validation coverage
• Verified GitHub Actions compatibility

Validation Performed

• Ruff linting passed
• Pytest validation passed
• CLI execution verified
• Windows execution validated
• Fedora Linux execution validated

Example CLI Usage

python -m sentinel_audit.main --format json
python -m sentinel_audit.main --format markdown
python -m sentinel_audit.main --format both
python -m sentinel_audit.main --output reports/custom-audit
python -m sentinel_audit.main --version

Architectural Impact

This update transitions SentinelAudit from a fixed execution workflow into a configurable operational security utility with flexible report handling and improved automation readiness.