# Quickstart: 023-clear-encounter

## Overview

Add a "Clear Encounter" feature that resets the entire encounter state (removes all combatants, resets round to 1, resets turn to 0) with a single confirmed action.

## Key Files to Create

| File | Layer | Purpose |
|------|-------|---------|
| `packages/domain/src/clear-encounter.ts` | Domain | Pure function: clear encounter state |
| `packages/application/src/clear-encounter-use-case.ts` | Application | Orchestrates domain call via store |
| `packages/domain/src/__tests__/clear-encounter.test.ts` | Test | Domain function tests |

## Key Files to Modify

| File | Change |
|------|--------|
| `packages/domain/src/events.ts` | Add `EncounterCleared` event type |
| `packages/domain/src/index.ts` | Export `clearEncounter` + event type |
| `packages/application/src/index.ts` | Export `clearEncounterUseCase` |
| `apps/web/src/hooks/use-encounter.ts` | Add `clearEncounter` callback |
| `apps/web/src/persistence/encounter-storage.ts` | Handle empty encounter in `loadEncounter` |
| `apps/web/src/components/turn-navigation.tsx` | Add clear button |
| `apps/web/src/App.tsx` | Wire `clearEncounter` to TurnNavigation |

## Architecture Pattern

Follow the existing remove-combatant pattern:

1. **Domain** (`clearEncounter`): Pure function, takes `Encounter`, returns `{ encounter, events }` or `DomainError`
2. **Application** (`clearEncounterUseCase`): Gets encounter from store, calls domain function, saves result
3. **Web hook** (`useEncounter`): Adds `clearEncounter` callback with `window.confirm()` gate
4. **UI** (`TurnNavigation`): Renders clear button, calls `onClearEncounter` prop

## Dev Commands

```bash
pnpm vitest run packages/domain/src/__tests__/clear-encounter.test.ts  # Run domain tests
pnpm check                                                              # Full merge gate
pnpm --filter web dev                                                   # Dev server
```