fix: retake all lab screenshots with correct tools and paths

- Retook 31 screenshots with proper tool installations (Java, Maven,
  ruff, lizard, golangci-lint) and correct working directories
- Fixed screenshot-manifest.json: src/utils/helpers.ts -> src/lib/helpers.ts
- Fixed capture-screenshots.ps1: dynamic Python Scripts path detection
- Created descriptive placeholders for 4 GitHub auth-required screenshots
- Fixed freeze command issues: pwsh wrapper, auto-sizing, temp file approach

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: emmanuelknafo