* Adds Kubernetes sandbox provisioner support
* Improves Docker dev setup by standardizing host paths
Replaces hardcoded host paths with a configurable root directory,
making the development environment more portable and easier to use
across different machines. Automatically sets the root path if not
already defined, reducing manual setup steps.
Defer sandbox acquisition and thread directory creation until first use to improve performance and reduce resource usage.
Changes:
- Add lazy_init parameter to SandboxMiddleware (default: true)
- Add ensure_sandbox_initialized() helper for lazy sandbox acquisition
- Update all sandbox tools to use lazy initialization
- Add lazy_init parameter to ThreadDataMiddleware (default: true)
- Create thread directories on-demand in AioSandboxProvider
- LocalSandbox already creates directories on write (no changes needed)
Benefits:
- Saves 1-2s Docker container startup for conversations without tools
- Reduces unnecessary directory creation and file system operations
- Backward compatible with lazy_init=false option
Co-authored-by: Claude Sonnet 4.5 <noreply@anthropic.com>
