Brownfield equivalent of new-project. Project exists, PROJECT.md has history. Gathers "what's next", updates PROJECT.md, then runs requirements → roadmap cycle.
Creates/Updates:
.planning/PROJECT.md— updated with new milestone goals.planning/research/— domain research (optional, NEW features only).planning/REQUIREMENTS.md— scoped requirements for this milestone.planning/ROADMAP.md— objective structure (continues numbering).planning/STATE.md— reset for new milestone
After: /df:plan-objective [N] to start execution.
Load project context: @.planning/PROJECT.md @.planning/STATE.md @.planning/MILESTONES.md @.planning/config.json
Load milestone context (if exists, from /df:discuss-milestone): @.planning/MILESTONE-CONTEXT.md