Point the lab-manual submodule at the verified environment fixes

Brings in the Windows setup-script fix (issue #14), the repaired test
suite, and three environment pins that CI now proves work: 42/42 on Linux,
Windows and macOS with nothing skipped. Before these, Windows could not
create the environment at all and three of the lab's own packages failed to
import.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01RA2V7NZ1hQ4fQSoZcBQgHp

Author: jeremymanning