Implementation plan: Approval choice reconciliation

Branch: gui/approval-reconcile-quality | Date: 2026-10-08 | Spec: spec.md

Summary

The cache currently remembers only a decision ID. Reuse the existing typed Decision snapshot and rebuild buttons when its ID, answerability or options change. Prompt-only updates retain buttons. No new helper or abstraction is needed.

Technical context

Rust 2021, minimum 1.92; existing GTK4 and VTE widgets. No dependencies, storage, protocol or core logic changes. Native test seam in terminal.rs can inspect the actual buttons, emitted actions and VTE identity.

Constitution check

Requirements precede code. Native red-green regression covers the GTK reconciliation defect. Existing light/dark acceptance and full verification remain mandatory. No ADR or constitution deviation is needed.

Project structure

crates/signaltty-gui/src/terminal.rs owns the cache, reconciliation and regression. docs/06-gui-toolkit.md records the corrected existing behavior. Selected evidence lives in docs/qa/.

Verification

Run the same native regression before and after, with answerability toggles, changed options and prompt-only updates. Inspect light/dark renders and run scripts/verify.sh full.