docs: update issue #450 with beta release execution log and lessons learned

- Mark all completed tasks and acceptance criteria as done
- Fix spec to reflect all four crates instead of SDK only
- Add token scope pre-flight requirement
- Update artifact verification section for all four crates
- Add Execution Log section documenting 12 issues found and fixed
  during the v0.1.0-beta.1 release run

Author: josecelano