# HyperTwist Phase S4-C Implementation Packet

Date: `2026-05-29`

Packet: `Phase S4-C`

Title: `first-party design shell skills`

## Outcome

Implemented now.

## Landed scope

- live `skill/translate-design-shell`
- live `skill/translate-design-interaction`
- bounded first-party design-shell translation state over authoritative
  first-party docs, design, browser, and packet source surfaces
- registry, control-state, audit-ledger, authoring-harness, sample-contract,
  and JSON round-trip support

## Preserved boundaries

- design-shell translation remains provenance-visible and bounded
- extraction and browser diagnostics remain separate prerequisite seams
- no generic browser-shell orchestration widening in this packet
- no broad workflow/review chaining widening in this packet

## Validation

- build target: `UnrealHyperTwistEditor Win64 Development`
- focused `S4-C` automation passed for design-shell coverage, bounded
  design-shell translation, and serialization round-trip
- `S4-B` regression passed after the new family landed
- full `Phase S1` skill substrate regression passed after the new family landed
