Brainstorm

Grill the user about a young roadmap item until its shape is clear: what it is, who it serves, which directions are chosen and which are dead. This is the expansion-stage interview — divergence is welcome, new branches are progress, and the item may leave bigger and rougher than a finalization pass would allow. tailrocks-finalize closes it later; this skill opens it up.

The deliverable is the updated item, not the conversation: every resolved answer lands in roadmap/<slug>/README.md the moment it resolves.

Boundaries