test(coverage): update test coverage metrics for dependencies.py

- Regenerate coverage report after adding 100 comprehensive tests
- Update is_tested flags for 12/13 functions in dependencies.py
- Overall coverage increased to 81.99% (551/672 functions tested)

Functions now marked as tested:
- is_external, run_astgrep, extract_package
- analyze_python_imports, analyze_typescript_imports
- analyze_file, analyze_directory, analyze_directory_optimized
- find_circular_dependencies, generate_report_text
- save_report_json, main

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Author: aledlie