workstreams.md referenced $GSD_TOOLS (6 occurrences) which is never
defined anywhere in the system. All other 60+ command files use the
standard $HOME/.claude/get-shit-done/bin/gsd-tools.cjs path. The
undefined variable resolves to empty string, causing all workstream
commands to fail with module not found.
Fixes#1766
Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>
