# HyperTwist Phase I-D reactive session-state environment cues implementation packet

Date: `2026-05-31`

## Outcome

`Phase I-D` is now landed locally as the fourth bounded HyperTwist-native
immersive packet.

## What landed

The current code now owns:

- a session-state cue contract
- a lighting-reaction boundary
- an audio-pacing boundary
- a mode-differentiation contract
- runtime-library accessors and focused automation coverage for the new
  reactive immersive cue surfaces

## Code surfaces

- `HyperTwistTrainingImmersiveEnvironmentLibrary.h/.cpp`
  - new first-party reactive cue surfaces inside the existing immersive
    environment bundle
- `HyperTwistTrainingRuntimeLibrary.h/.cpp`
  - runtime accessors for the `Phase I-D` immersive cue packet
- `HyperTwistImmersivePhaseIDReactiveCueContractTest.cpp`
  - focused automation for session-state, lighting/audio pacing, and
    mode-differentiation assertions

## Boundedness preserved

This packet does **not** claim:

- generic VFX ownership
- broad soundtrack scoring ownership
- cross-product mode framework ownership
- theatrical spectacle transitions
- later immersive hardening work such as performance budgets or reduced-effects fallback

The slice remains a training-native reactive-cue follow-on above `Phase I-A`
through `Phase I-C`.

## Canon impact

The HyperTwist canon now records:

- `Phase I-A` scenic virtual training environment foundations is landed
- `Phase I-B` immersion and focus-presence controls is landed
- `Phase I-C` spatial coaching and tutorial staging is landed
- `Phase I-D` reactive session-state environment cues is landed
- the then-next deliberate immersive seam, `Phase I-E` comfort, accessibility, and performance hardening, is now also landed
- the immersive lane remains HyperTwist-native and training/runtime oriented
- the lane still does not become a generic virtual desktop shell, generic VFX stack, soundtrack system, or cross-product mode framework
