docs: [#117] update issue specification to match current implementation

- Replace 'ToolInstaller' with 'DependencyInstaller' throughout
- Replace 'ToolDetector' with 'DependencyDetector' throughout
- Update CLI examples to use --dependency flag (not --tool)
- Document handler-based architecture in handlers/ directory
- Add exit codes documentation (0, 1, 2, 3)
- Add comprehensive log level control examples
- Emphasize automation-focused design (no user interaction)
- Remove temporary docs files (117-github-issue-updated.md, 117-proposed-updates.md, 117-update-summary.md)
- Update GitHub issue #117 description with aligned content

Author: josecelano