Blueprint Template (Light, <=5 tasks)

Skeleton keeps all 8 section numbers so Forge gates (§4 milestones, §8 change log) hold; only 4 sections are required reading.

# Build Blueprint vX.Y | Status: draft/confirmed
## 1. Goals & Non-Goals
## 2. Success Criteria (checkable)
## 3. Technical Approach (one line; expand only if contended)
## 4. Milestones (single M1 with exit criterion)
## 5. Task List
- [ ] S1-T1 <task> | Acceptance: ... | M1
## 6. Acceptance Criteria
## 7. Risks & Assumptions (one line; expand only if contended)
## 8. Change Log
- v1.0 ...