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
