Migrate GSD-2 projects to GSD v1

Migrate GSD-2 (.gsd/) project to GSD v1 (.planning/) format

Reverse-migrating legacy GSD-2 projects back to v1 format while preserving completion state and phase hierarchy.

• · GSD-2 project directory with .gsd/ structure
• · Optional --path <dir> to specify migration source
• · Optional --force flag to overwrite existing .planning/

• · GSD v1 .planning/ directory with ROADMAP.md, phases/, STATE.md, config.json
• · File list and migration statistics
• · Preserved completion state and phase order

• · gsd-tools.cjs (CJS-only, not on gsd-sdk registry)
• · node

• · .gsd/ directory exists (or --path provided)
• · gsd-tools.cjs available at ~/.claude/get-shit-done/bin/
• · .planning/ does not exist (or --force provided)

• · .gsd/ not found → error reported, migration stops
• · .planning/ exists without --force → stops before overwrite
• · Milestone/slice/task structure malformed → migration reports partial failures
• · GSD-2 cost ledger, database state, VS Code extension state → cannot be migrated (documented limitation)

• · Non-destructive: .gsd/ never modified
• · Dry-run preview before write
• · Completion state and numbering preserved
• · User confirmation gate before any file writes