Add persistent workspace shell sessions

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.

README.md

@@ -20,7 +20,7 @@ It exposes the same runtime in three public forms:
 - First run transcript: [docs/first-run.md](docs/first-run.md)
 - Terminal walkthrough GIF: [docs/assets/first-run.gif](docs/assets/first-run.gif)
 - PyPI package: [pypi.org/project/pyro-mcp](https://pypi.org/project/pyro-mcp/)
-- What's new in 2.4.0: [CHANGELOG.md#240](CHANGELOG.md#240)
+- What's new in 2.5.0: [CHANGELOG.md#250](CHANGELOG.md#250)
 - Host requirements: [docs/host-requirements.md](docs/host-requirements.md)
 - Integration targets: [docs/integrations.md](docs/integrations.md)
 - Public contract: [docs/public-contract.md](docs/public-contract.md)
@@ -57,7 +57,7 @@ What success looks like:
 ```bash
 Platform: linux-x86_64
 Runtime: PASS
-Catalog version: 2.4.0
+Catalog version: 2.5.0
 ...
 [pull] phase=install environment=debian:12
 [pull] phase=ready environment=debian:12
@@ -78,6 +78,7 @@ After the quickstart works:
 - prove the full one-shot lifecycle with `uvx --from pyro-mcp pyro demo`
 - create a persistent workspace with `uvx --from pyro-mcp pyro workspace create debian:12 --seed-path ./repo`
 - update a live workspace from the host with `uvx --from pyro-mcp pyro workspace sync push WORKSPACE_ID ./changes`
+- open a persistent interactive shell with `uvx --from pyro-mcp pyro workspace shell open WORKSPACE_ID`
 - move to Python or MCP via [docs/integrations.md](docs/integrations.md)
 
 ## Supported Hosts
@@ -131,7 +132,7 @@ uvx --from pyro-mcp pyro env list
 Expected output:
 
 ```bash
-Catalog version: 2.4.0
+Catalog version: 2.5.0
 debian:12 [installed|not installed] Debian 12 environment with Git preinstalled for common agent workflows.
 debian:12-base [installed|not installed] Minimal Debian 12 environment for shell and core Unix tooling.
 debian:12-build [installed|not installed] Debian 12 environment with Git and common build tools preinstalled.
@@ -209,6 +210,10 @@ longer-term interaction model.
 pyro workspace create debian:12 --seed-path ./repo
 pyro workspace sync push WORKSPACE_ID ./changes --dest src
 pyro workspace exec WORKSPACE_ID -- cat src/note.txt
+pyro workspace shell open WORKSPACE_ID
+pyro workspace shell write WORKSPACE_ID SHELL_ID --input 'pwd'
+pyro workspace shell read WORKSPACE_ID SHELL_ID
+pyro workspace shell close WORKSPACE_ID SHELL_ID
 pyro workspace logs WORKSPACE_ID
 pyro workspace delete WORKSPACE_ID
 ```
@@ -217,8 +222,10 @@ Persistent workspaces start in `/workspace` and keep command history until you d
 machine consumption, add `--json` and read the returned `workspace_id`. Use `--seed-path` when
 you want the workspace to start from a host directory or a local `.tar` / `.tar.gz` / `.tgz`
 archive instead of an empty workspace. Use `pyro workspace sync push` when you want to import
-later host-side changes into a started workspace. Sync is non-atomic in `2.4.0`; if it fails
-partway through, delete and recreate the workspace from its seed.
+later host-side changes into a started workspace. Sync is non-atomic in `2.5.0`; if it fails
+partway through, delete and recreate the workspace from its seed. Use `pyro workspace exec` for
+one-shot non-interactive commands inside a live workspace, and `pyro workspace shell *` when you
+need a persistent PTY session that keeps interactive shell state between calls.
 
 ## Public Interfaces