Let agents inhabit a workspace across separate calls instead of only submitting one-shot execs.
Add workspace shell open/read/write/signal/close across the CLI, Python SDK, and MCP server, with persisted shell records, a local PTY-backed mock implementation, and guest-agent support for real Firecracker workspaces.
Mark the 2.5.0 roadmap milestone done, refresh docs/examples and the release metadata, and verify with uv lock, UV_CACHE_DIR=.uv-cache make check, and UV_CACHE_DIR=.uv-cache make dist-check.
Break the updated workspace vision into a checked-in roadmap from 2.4.0 through 3.1.0 so later implementation can be driven milestone by milestone.
Link the roadmap from the vision doc and keep each release slice scoped to one product capability, from the workspace contract pivot through shells, export/diff, services, snapshots, secrets, networking, and GA promotion.
This is a docs-only planning scaffold; runtime behavior stays unchanged in this commit.
