docs: update autoloop Go migration progress to iteration 170

- Latest status: iteration 170, best metric 1115.07%, PR #59
- Updated original_python_lines to 87,626 (from 71,696)
- Updated migrated_python_lines to 935,411
- Module count: 317 entries (199 distinct Go packages, 5 source-migrated)
- Replaced stale 141-row module table with current data from
  benchmarks/migration-status.json: 5 source-migrated + 199 test-migrated
  Go packages
- Updated migration progress table through iteration 170 with
  workflow run links for iters 163-170
- Updated Go build/test validation signals to iters 168-170
- Updated next-up section from memory/autoloop Current Priorities
- Updated last-updated timestamp to 2026-05-21 05:19 UTC

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

Author: github-actions[bot]