* add pre-baked microsandbox image
Bake openwork, openwork-server, and the pinned opencode binary into a single Docker image so micro-sandbox remote-connect smoke tests can boot quickly and be verified with curl and container health checks.
* add Rust microsandbox example
Add a standalone microsandbox SDK example that boots the OpenWork image, validates remote-connect endpoints, and streams sandbox logs so backend-only sandbox behavior can be exercised without Docker.
* exclude Rust example build output
Keep the standalone microsandbox example in git, but drop generated Cargo target artifacts so the branch only contains source, docs, and lockfile.
* test
* add microsandbox feature flag for sandbox creation
Made-with: Cursor
* refactor sandbox mode isolation
Made-with: Cursor
