Extend SandboxMode enforcement from bash to the filesystem tools, the sandbox
RFC's deferred cross-family phase.
- dsh-sandbox-policy (new, ctx.sandboxPolicy): the single home for the
deployment default mode + workspaceRoot and the per-session override event,
renamed bash/sandbox-mode -> sandbox/mode and moved here with its fold/setter.
Decouples the bash seam from dsh-session.
- dsh-fs-sandbox (new): SandboxedFileSystem extends LocalFileSystem and fences
write/edit by the per-call mode (read-only denies, workspace-write contains to
the workspace + temp roots via the shared writableRoots, danger passes
through); reads pass through. Structured FS_SANDBOX_DENIED; in-lock parent
re-canonicalization. A policy fence in trusted code, not a kernel boundary.
- dsh-sandbox: the shared escalation kit (writableRoots, the strictly-wider
ladder, denial/hint markers, approveEscalation) both tool families use;
approveEscalation takes a structural approver so dsh-sandbox gains no
approval/agent dependency, and both tools stay duplication-free.
- tool-fs: write/edit advertise sandbox_permissions/justification under a
confining ctx.fs, map FS_SANDBOX_DENIED to the shared [sandbox: ...] marker,
and resolve the same one-approved-wider retry.
- examples/acp-agent: composes sandbox-policy + fs-sandbox, drops the gating
that disabled the fs stack under confined modes.
RFC docs/rfc/implemented/feature/2026-07-14-cross-family-fs-sandbox.md; the old
sandbox RFC's In-process/deferred/FAQ sections updated to shipped fact.
The executable golden proves the packaged VFS and Python SDK boundary, but it does not pin the editor-facing ACP updates, and the existing ACP scenarios exercised Code Mode, subagents, and workflows only as separate stories.
Add a dedicated both-mode replay composition that mounts a Cordis marker, inspects it through a real Code Mode worker dispatch, runs a direct spawn child and a workflow-owned spawn child, then unmounts the marker. Commit normalized ACP frames, parent and child logs, and the composition-specific request-header pin.
Use cordis_inspect as the Code Mode sub-dispatch instead of registering another dynamic tool: the executable snapshot already owns tool-set mutation and header-delta coverage, while this keeps the ACP header contract stable and focuses the new golden on transport presentation and cross-feature composition.
Tianyi Cui