feat: add interactive prompts and smart patch selection

- Add shared confirm() and select_one() prompt utilities to output.rs
- Smart patch selection: paid users auto-select best paid patch per PURL,
  free users with multiple patches get dialoguer interactive selection
- Default-YES confirmation prompts (Y/n) for get, scan, and remove
- Add -y/--yes flag to scan and remove commands to skip prompts
- JSON mode never prompts; returns selection_required error with full
  vulnerability details when explicit selection is needed
- Scan now shows detailed patch summary (severity, CVEs, descriptions)
  before confirming download
- Remove shows what will be removed before confirming rollback
- Extract download_and_apply_patches() shared between get and scan
- Add patch update detection in scan table and download flow

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: mikolalysenko