refactor: update commands, workflows, agents for gsd-tools integration
Commands (15): audit-milestone, complete-milestone, debug, execute-phase,
help, insert-phase, new-milestone, new-project, plan-milestone-gaps,
plan-phase, progress, quick, remove-phase, research-phase, verify-work
Workflows (22): execute-plan (69% reduction), verify-phase (55%), others
Agents (14): All updated for new workflow structure
Total token savings: ~22k chars (75.6% in affected sections)
Ported from: get-shit-done-v2@d1fb2d5, 7f79a9b
d44c7dcc9b