CLI: Update SDK to c6c0c0d and add agents auth + browsers process/fs watch commands

- Update kernel-go-sdk to v0.26.1-0.20260117213330-c6c0c0d711e9
- Add agents auth commands: create, get, list, delete
- Add agents auth invocations commands: create, get, exchange, submit
- Add browsers process resize command
- Add browsers fs watch commands: start, stop, events

Author: Cursor Agent