f4707745bf
Add the system-completion design doc (risk-first milestones M1-M10): Phase 1 Stabilize (M1 runtime wiring, M2 correctness, M3 script trust boundary, M4 doc reconciliation) then Phase 2 Expand (M5-M10 feature epics). Scope = all Tier 1/2/4 + in-scope Tier 3 features; T12/T19 deferred to own brainstorm; deliberate anti-goals excluded. Also commit the source audit (stillpending.md).