# Slice 4f: automation, lifecycle, effects and ceilings

Implemented September 6, 2026. Production integration is in `visual-engine.js`, `visual-automation.js`, `visual-lifecycle.js`, `visual-effects.js`, `visual-subsystem.js`, the shared resolver and action executor.

Automation uses the audio interpolation implementation and adds visual repeat/ping-pong time folding. Public numeric visual targets enter the existing binding/automation/override/modulation/clamp stages. Internal graphic and procedural channels remain private. Tracks resolve once in scope order, including independent spawn scope sampling; behavior collisions reject at import. Viewport camera defaults continue to participate in the pipeline.

Spawn and remove actions use PRD 28's `target`, `with`, optional `lifetime`, and `instances.*` addressing. Instances enter the layer on their next tick, retain independent resource-owner and originating-scenario relationships, fade without rewriting authored opacity, and reclaim tracks and item state at disposal/failure. Instance, track and point budget refusal is atomic and does not consume an ordinal. Runtime failure is isolated to its system. Scenario orchestration remains Phase 6; its cleanup integration surface is `VisualEngine.cleanup(owner)`.

All seven effects execute against frame pixels in authored order. Grain has no access to seeded streams. Blur/bloom use a separable approximation and report it once per effect. Unavailable effects skip with a diagnostic. The specification's stray sentence exposing boolean `enabled` conflicted with the four-family numeric target table; it now explicitly follows that table and remains once-resolved.

Aggregate particle, emitter, trail, link and field budgets enforce the section 19.5 shedding rules. Field work is ordered nearest-first; particle/item eviction chooses the largest population and its oldest item. Existing buffer/backing-store enforcement and new effect pass and spawn/automation admission use centralized values. Diagnostic accounting counts logical ticks rather than repeated refusals in a tick.

`test/phase4-execution.test.mjs` adds twenty execution tests: curves/modes, loops, shared override release, sampling order, lifecycle edges, zero release, ownership/forced cleanup, atomic budgets, actions, known effect pixels and order, stream independence, unavailable effects, diagnostic recovery, population/history/link/field overloads, resolved count limits and failure isolation. Existing camera/projection and structural validation tests remain in the renderer/contract suites.

No hardware performance result is claimed. Ceiling values and frame-time governance thresholds remain provisional until 4h. Post-effect pixel checks establish operation, not perceptual equivalence on a real display. No live audio acceptance or full scenario execution is claimed.

## Final verification

All **223 checks pass** across fourteen test files, including the twelve GC2 fixture checks and 109 Phase 4 tests. The sandbox blocks Node's default child-process test isolation (`spawn EPERM`), so each file was run separately with `node --test --test-isolation=none`. Running GC2 in the same process as other suites is insufficient because its legacy runner exits the process; the separate invocations avoid silently skipping later tests.

Production and acceptance build determinism and bundled JavaScript syntax pass; `git diff --check` is clean. Generated artifact SHA-256 values:

- `XZBT.html`: `46619d8ff2fbadf188136409d5cfe658bf5492ba0ba111d58ad488e95b343770`
- `prototypes/phase4/XZBT-visual-acceptance.html`: `4298121998e7532f0824139c48ccab6b8c022ccf6a8079cf3672cded4bc6db74`