d574968da4
- Replaced manual settings callback sets with a shared `SettingSignal` that snapshots listeners and skips over individual callback failures. - Updated `provider.appendOnlyContext`, `statusLine.sessionAccent`, and `hindsight` hook dispatch to use the new signal and added a Settings test confirming a throwing append-only listener does not stop other listeners. - Adjusted the duplicate-tool-results regression test to handle `tool_calls` being absent before mapping IDs.