v0.6.0 — one-pager/BRD

New template: one-pager, for pitching one direction and getting fast alignment before a full PRD or a formal decision doc gets written. BRD is treated as a heavier weight-tier of the same template (optional stakeholders/rough-milestones), not a separate one — neither external one-pager/PR-FAQ standards nor the org's own real docs draw a hard line between them.

prd picks up three small additions from real-world heavier PRD templates (optional lead pitch, strategic-fit prompt, assumptions-check prompt); sign-off gates, DARCI tables, and launch-plan mechanics stay out as org process, not brainstorming-stage spec content.

Full changes in the CHANGELOG.