defer-lastaction-overwrite

# DEFER lastAction Overwrite

Substeps 1.1 and 1.2 both DEFER. The runtime tags 1.1's transition with
`action: DEFER`. On 1.2's transition the parent's PASS ALL aggregation
resolves; the compiler overwrites the terminal transition's lastAction so
consumers observe `action: COMPLETE, aggregated: true` — not the raw
`DEFER`. This pins down compiler.ts around the aggregation-emit site.

## 1. Validate

- PASS ALL COMPLETE
- FAIL ANY STOP

### 1.1 First check

- DEFER

```bash
rd echo "first"
```

### 1.2 Second check

- DEFER

```bash
rd echo "second"
```