Add model-native workspace file operations

Remove shell-escaped file mutation from the stable workspace flow by adding explicit file and patch tools across the CLI, SDK, and MCP surfaces.

This adds workspace file list/read/write plus unified text patch application, backed by new guest and manager file primitives that stay scoped to started workspaces and /workspace only. Patch application is preflighted on the host, file writes stay text-only and bounded, and the existing diff/export/reset semantics remain intact.

The milestone also updates the 3.2.0 roadmap, public contract, docs, examples, and versioning, and includes focused coverage for the new helper module and dispatch paths.

Validation:
- uv lock
- UV_CACHE_DIR=.uv-cache make check
- UV_CACHE_DIR=.uv-cache make dist-check
- real guest-backed smoke for workspace file read, patch apply, exec, export, and delete

examples/python_workspace.py

@@ -31,6 +31,27 @@ def main() -> None:
         workspace_id = str(created["workspace_id"])
         try:
             pyro.push_workspace_sync(workspace_id, sync_dir)
+            files = pyro.list_workspace_files(workspace_id, path="/workspace", recursive=True)
+            print(f"workspace_entries={len(files['entries'])}")
+            note = pyro.read_workspace_file(workspace_id, "note.txt")
+            print(note["content"], end="")
+            written = pyro.write_workspace_file(
+                workspace_id,
+                "src/app.py",
+                text="print('hello from file ops')\n",
+            )
+            print(f"written_bytes={written['bytes_written']}")
+            patched = pyro.apply_workspace_patch(
+                workspace_id,
+                patch=(
+                    "--- a/note.txt\n"
+                    "+++ b/note.txt\n"
+                    "@@ -1 +1 @@\n"
+                    "-hello from sync\n"
+                    "+hello from patch\n"
+                ),
+            )
+            print(f"patch_changed={patched['changed']}")
             result = pyro.exec_workspace(workspace_id, command="cat note.txt")
             print(result["stdout"], end="")
             secret_result = pyro.exec_workspace(