Add workspace export and baseline diff

Complete the 2.6.0 workspace milestone by adding explicit host-out export and immutable-baseline diff across the CLI, Python SDK, and MCP server.

Capture a baseline archive at workspace creation, export live /workspace paths through the guest agent, and compute structured whole-workspace diffs on the host without affecting command logs or shell state. The docs, roadmap, bundled guest agent, and workspace example now reflect the new create -> sync -> diff -> export workflow.

Validation: uv lock, UV_CACHE_DIR=.uv-cache make check, UV_CACHE_DIR=.uv-cache make dist-check, and a real guest-backed Firecracker smoke covering workspace create, sync push, diff, export, and delete.

src/pyro_mcp/api.py

@@ -130,6 +130,22 @@ class Pyro:
     def logs_workspace(self, workspace_id: str) -> dict[str, Any]:
         return self._manager.logs_workspace(workspace_id)
 
+    def export_workspace(
+        self,
+        workspace_id: str,
+        path: str,
+        *,
+        output_path: str | Path,
+    ) -> dict[str, Any]:
+        return self._manager.export_workspace(
+            workspace_id,
+            path=path,
+            output_path=output_path,
+        )
+
+    def diff_workspace(self, workspace_id: str) -> dict[str, Any]:
+        return self._manager.diff_workspace(workspace_id)
+
     def open_shell(
         self,
         workspace_id: str,
@@ -370,6 +386,20 @@ class Pyro:
             """Return persisted command history for one workspace."""
             return self.logs_workspace(workspace_id)
 
+        @server.tool()
+        async def workspace_export(
+            workspace_id: str,
+            path: str,
+            output_path: str,
+        ) -> dict[str, Any]:
+            """Export one file or directory from `/workspace` back to the host."""
+            return self.export_workspace(workspace_id, path, output_path=output_path)
+
+        @server.tool()
+        async def workspace_diff(workspace_id: str) -> dict[str, Any]:
+            """Compare `/workspace` to the immutable create-time baseline."""
+            return self.diff_workspace(workspace_id)
+
         @server.tool()
         async def shell_open(
             workspace_id: str,