Spawns sub-agents in parallel to perform concurrent tasks.
## Usage
```json
{
"tasks": [
{"agentName": "codebase-explorer", "prompt": "Find all API endpoints"},
{"agentName": "rust-code-monkey", "prompt": "Write tests for auth module"}
]
}
```
- `tasks` — **required**, array of task objects
- `agentName` — agent name from project `.aether/settings.json` (`agents[].name`) with `agentInvocable: true`
- `prompt` — task for the agent to perform
All agents execute in parallel. Results returned when ALL complete.