Refresh docs and examples for workspaces

Rewrite the user-facing persistent sandbox story around pyro workspace ..., including the install guide, first-run transcript, integrations notes, and public contract reference.

Rename the Python example to examples/python_workspace.py and update the docs to use the new workspace create, sync, exec, status, logs, and delete flows with seed_path/workspace_id terminology.

Mark the 2.4.0 workspace-contract pivot as done in the roadmap now that the shipped CLI, SDK, MCP, docs, and tests all use the workspace-first surface.

docs/roadmap/task-workspace-ga/2.4.0-workspace-contract-pivot.md

@@ -1,5 +1,7 @@
 # `2.4.0` Workspace Contract Pivot
 
+Status: Done
+
 ## Goal
 
 Make the public product read as a workspace-first sandbox instead of a
@@ -16,7 +18,7 @@ task-flavored alpha by replacing the `task_*` surface with `workspace_*`.
   - `pyro workspace delete`
 - SDK:
   - `create_workspace`
-  - `sync_push_workspace`
+  - `push_workspace_sync`
   - `exec_workspace`
   - `status_workspace`
   - `logs_workspace`