Why: the matrix scoped native work to the pi wrapper's exposed surface; the full-agent batch deliberately expands beyond it, so the new domains need their own acceptance basis recorded (standard conformance + negative tests + product acceptance, not pi comparison) plus honest security boundary notes. Evidence: docs-only change; go vet/test unaffected (verified green in the code commits this branch carries). Impact: docs/parity-matrix.md gains the R15 expansion table mapping every domain to its test evidence; README package table reflects the new runtime/mcp, runtime/skills, runtime/promptx, runtime/subagent packages and the v0.2 exec port. Refs: docs/parity-matrix.md #1-#16 remain valid for wrapper-parity rows.