commits
## Summary
- refactor `emit_event` to accept primitive params
- update generator logic for new signature
- adjust unit tests
## Testing
- `./scripts/check.sh`
## Summary
- emit shutdown event when the generator loop fully exits
- have ServeLoop evict generators based on `.shutdown`
- update generator docs with shutdown lifecycle event
- expect shutdown frames in tests
## Testing
- `./scripts/check.sh`
- `cd docs && npm run build`
## Summary
- update generator runtime with Task struct and typed events
- emit parse errors instead of spawn errors
- adjust ServeLoop and docs for new protocol
- add unit test for emit_event helper
## Testing
- `./scripts/check.sh`
- `cd docs && npm run build`
## Summary
- unify generator scripts with handler/command config format
- support `return_options` and `duplex` in generator scripts
- document new generator configuration
- adjust generator tests
## Testing
- `./scripts/check.sh`