Merge remote-tracking branch 'origin/master' into worktree/docs-website

# Conflicts:
#	website/.vitepress/config/api-sidebar.json
#	website/zh-CN/api/harness/bash-env.md
#	website/zh-CN/api/harness/bash.md
#	website/zh-CN/api/harness/events.md
#	website/zh-CN/api/harness/fs.md
#	website/zh-CN/api/harness/permission.md
#	website/zh-CN/api/harness/sandbox.md

.agents/notes/implemented/feature/2026-07-06-sandbox.md

@@ -96,7 +96,7 @@ The default is composition config (`cordis.yml`) — operator-owned, process-wid
 
 ```ts
 interface SessionEventMap {
-  'bash/sandbox-mode': { mode: 'read-only' | 'workspace-write' | 'danger-full-access' }
+  'sandbox/mode': { mode: 'read-only' | 'workspace-write' | 'danger-full-access' }
   'approval/policy': { policy: 'ask' | 'never' }
 }
 ```
@@ -111,9 +111,7 @@ Sandbox mode is not narrated in the prompt; denial results report the mode when
 
 #### In-process tools
 
-fs/web/todo execute in-process, so their sandbox semantics are policy at their seams: the fs intent gates deciding by the shared mode vocabulary (§ Deferred phases, cross-family) make `read-only` a real boundary instead of a bash-only approximation — until then the contract says so honestly. No generic per-tool sandbox runtime: a host-mediated tool leaves the process only by returning declarative effects the host validates, which is a rewrite, not a wrapper.
-
-FIXME: Revisit this tool-local boundary. The follow-up design needs to determine whether sandboxing becomes a global harness capability that applies uniformly to every tool, instead of expressing in-process enforcement independently at each tool seam.
+fs/web/todo execute in-process, so their sandbox semantics are policy at their seams. The fs seam now enforces the shared mode vocabulary through a sandboxed provider (`dsh-fs-sandbox` fences write/edit by mode; see [the cross-family fs sandbox RFC](2026-07-14-cross-family-fs-sandbox.md)), so `read-only`/`workspace-write` are real boundaries for the filesystem tools, not a bash-only approximation. web/todo remain unfenced (web's only effect is network, outside the file-effect mode vocabulary). No generic per-tool sandbox runtime: a host-mediated tool leaves the process only by returning declarative effects the host validates, which is a rewrite, not a wrapper — the follow-up settled on one shared policy home (`ctx.sandboxPolicy`) with per-seam enforcement, not a uniform wrapper.
 
 ### Testing
 
@@ -126,8 +124,7 @@ FIXME: Revisit this tool-local boundary. The follow-up design needs to determine
 
 Each phase gets its full design when picked up, validated against the code at that time, and lands with unit, real-API e2e, and snapshot coverage at the tiers it touches.
 
-- **Per-session workspace root** — the executor's write boundary stays config-fixed for its lifetime while each ACP session has its own cwd; a per-session root rides the same per-call policy carrier once designed.
-- **Cross-family boundary** — the fs intent gates decide by the shared mode, making `read-only`/`workspace-write` real boundaries beyond bash.
+- **Per-session workspace root** — the executor's write boundary stays config-fixed for its lifetime while each ACP session has its own cwd; a per-session root rides the same per-call policy carrier once designed. Centralizing the root on `ctx.sandboxPolicy` (the [cross-family fs sandbox RFC](2026-07-14-cross-family-fs-sandbox.md)) is the groundwork.
 - **Second consumer** — `subagent-acp` optionally confines child agents (per-call policy; unconfined default — a child agent must write its own persistence).
 - **More environments** — an environment-coherent capability group example (e.g. bash+fs against one container).
 - **Windows chain** — `PLATFORM_CHAINS.win32` is reserved and empty (fail-closed); filling it means a confinement runner from the AppContainer/restricted-token family, shipped from its own repository on the `node-addon-landlock-run` template, plus its profile dialect and denial/runner-failure signatures.
@@ -171,7 +168,7 @@ What shipped pins — the tiers in Testing hold each:
 Costs and accepted limits:
 
 - **The one-wrapper illusion is given up knowingly.** A `tools/pre-execute` wrapper plus prompt conventions does not solve sandbox approval — the correct design costs structured denials, native runner probes, per-call policy carriage, and consistent cross-family enforcement, and this design pays it.
-- **`read-only` is not yet a cross-family boundary.** Until the fs intent gates decide by the shared mode, the claim holds for bash only; the contract says so honestly (§ In-process tools).
+- **`read-only` became a cross-family boundary through a follow-up.** This RFC shipped bash-only enforcement; the [cross-family fs sandbox RFC](2026-07-14-cross-family-fs-sandbox.md) extends the same mode vocabulary to the filesystem tools through a sandboxed `ctx.fs` provider and relocates the mode/root config and the `sandbox/mode` override to `ctx.sandboxPolicy` (§ In-process tools).
 - **Windows has no backend.** Its chain slot is reserved empty — fail-closed, never a fallthrough; filling it is a deferred phase.
 - **The Seatbelt rung leans on Apple's deprecated-but-shipped `sandbox-exec` CLI.** As darwin's sole candidate it is selected without probing, so a future removal surfaces at execution as the runner-failure classification — re-thrown `SANDBOX_UNAVAILABLE`, the command never runs; fail closed, never open.
 - **Landlock confinement is only as complete as the running kernel's ABI.** Reported as `enforcement: 'partial'` rather than refused — the deliberate trade that keeps the fallback available on older-kernel hosts.
@@ -191,9 +188,9 @@ Costs and accepted limits:
 - **What happens on a platform with no backend — Windows today?** `confine()` throws the fail-closed `SANDBOX_UNAVAILABLE` and the command never spawns; `win32` is a reserved EMPTY chain, pinned by test to fail closed identically until a Windows runner fills it (§ Deferred phases).
 - **`bwrap` is installed on my host but unusable (disabled unprivileged userns, an LSM denying `mount`) — what happens?** The chain probe is functional — it builds and enforces a real profile rather than checking `--version` — so a present-but-unusable `bwrap` fails its probe, selection falls to the registry-installed Landlock launcher, and the verdict is cached for the provider's lifetime.
 - **Does the sandbox restrict network or process visibility?** No — `SandboxMode` claims FILE effects only; the bwrap profile deliberately does not unshare pid, and no backend claims network. Whether network restriction becomes its own knob is left open in § The seam.
-- **Which tools actually run confined?** OS subprocesses through `ctx.bash` — the bash tools, and hook commands transitively. fs/web/todo execute in-process, where an `execve` wrapper is mechanically meaningless; their `read-only` semantics arrive with the cross-family deferred phase, and until then the contract says bash-only honestly.
+- **Which tools actually run confined?** OS subprocesses through `ctx.bash` — the bash tools, and hook commands transitively — plus the filesystem tools (`read`/`write`/`edit`) through the sandboxed `ctx.fs` provider (the [cross-family fs sandbox RFC](2026-07-14-cross-family-fs-sandbox.md)): bash confines via the OS runner, fs via an in-process path fence, both keying off the same `ctx.sandboxPolicy` mode. web/todo stay in-process and unfenced (web's only effect is network, outside the file-effect mode vocabulary).
 - **Does a granted escalation persist?** No. The grant is consumed by the exact foreground or background call that asked; every neighboring call keeps its own effective mode. A later background denial surfaces through `task_output` and may ground a new exact-command retry.
-- **When does an editor's mode switch take effect?** Mid-turn: appended immediately, honored by the very next call's stamp. Idle: held on the bridge's session record, anchored at the next turn's `agent/prompt-submit`, with N flips coalescing to at most one event (none if net-zero); a crash before anchoring reverts it and `session/load` reports the truth. The model is not told — its next command simply behaves under the new mode.
+- **When does an editor's mode switch take effect?** Mid-turn: appended immediately, honored by the very next call's stamp. Idle: held on the bridge's session record, anchored at the next `agent/prompt-submit` inside its open turn, with N flips coalescing to at most one event (none if net-zero); a crash before anchoring reverts it and `session/load` reports the truth. The model is not told — its next command simply behaves under the new mode.
 - **What survives a restart — and what if the operator changed the config default while the process was down?** Overrides replay from the session log (`effective = fold ?? config`), so a resumed session keeps its modes with zero catch-up machinery; a default that drifted offline changes behavior the same way a switch does (the approval policy, being stated, is additionally narrated with operator/config attribution).
 - **What does `enforcement: 'partial'` on a result mean?** The selected backend enforces the subset its kernel ABI governs — e.g. Landlock before ABI v3 does not govern path truncate — and says so structurally instead of refusing the host; the probe's report line distinguishes the cases. The bwrap and Seatbelt profiles govern every promised file effect by construction, so they always report `full`.
 

.agents/notes/implemented/feature/2026-07-14-cross-family-fs-sandbox.i18n.yaml

@@ -0,0 +1,6 @@
+# Bilingual-pair consistency record (docs/i18n/README.md): the git blob hash of each
+# side as of the last confirmed-consistent state. Both languages carry equal authority;
+# after editing either side, bring the other along and re-record with:
+#   pnpm run verify-translation-pairing --write
+2026-07-14-cross-family-fs-sandbox.md: 9b6312e5994469606bd1645902fc798f70258580
+2026-07-14-cross-family-fs-sandbox.zh.md: d4816e03d94bdf12b2db875d71dccb7db3a2c0d7

.agents/notes/implemented/feature/2026-07-14-cross-family-fs-sandbox.md

@@ -0,0 +1,94 @@
+# Agent Note: Cross-family file sandbox — one policy home, a sandboxed fs provider, and fs escalation parity
+
+Status: implemented
+
+English | [中文](2026-07-14-cross-family-fs-sandbox.zh.md)
+
+## Problem
+
+`SandboxMode` claims file effects, but originally only `ctx.bash` enforced it. The fs tools (`write`/`edit`) mutate the host filesystem in-process through `ctx.fs`, where an OS argv wrapper is mechanically meaningless — [the sandbox Agent Note](2026-07-06-sandbox.md) § In-process tools records this and left cross-family enforcement as a deferred phase with an open question: whether in-process enforcement stays per-seam or becomes a uniform harness capability. This Agent Note is that phase, and answers it: one shared policy home, per-seam enforcement at each family's correct altitude.
+
+The gap was not read-only-shaped. A confined coding agent's product mode is `workspace-write`: bash may already write under the workspace root while everything outside is denied, so an fs enforcement that could only deny-all would be strictly worse than disabling the fs tools — the model would attempt an in-workspace `write`, be denied, and learn to detour through `bash` heredocs. Cross-family enforcement therefore speaks the full mode ladder, including the path-containment judgment `workspace-write` requires (canonical targets; `..`/symlink/absolute-path escapes) and the same escalation lever bash carries.
+
+A second enforcing family also exposed an ownership problem in the original layout. The deployment default (`mode` + `workspaceRoot`) was configured on `dsh-bash-sandbox`, and the per-session override event was `bash/sandbox-mode`, folded and written by `dsh-bash`'s session-mode kit. With fs enforcing the same policy, either fs reads bash's config and events (a capability family depending on a sibling's plugin config) or each family carries its own copy — and two copies of `workspaceRoot` drift into exactly the split world the sandbox RFC warns about: bash confined to one root while fs fences another.
+
+## Decision
+
+Three coordinated pieces, all composed from the leaf `cordis.yml`, none touching `agent-loop`.
+
+### `ctx.sandboxPolicy` — one home for mode and workspace root
+
+`packages/sandbox/sandbox-policy/` (`@deepseek-ai/dsh-sandbox-policy`) registers `ctx.sandboxPolicy`, the single owner of the deployment's sandbox policy:
+
+- `Config`: `mode` (the closed `SandboxMode` union, default `read-only`) and `workspaceRoot` (default the process cwd, resolved absolute). Misconfiguration fails loud at load.
+- The per-session override event `sandbox/mode`, with its pure fold (`effectiveSandboxMode(events)`), its write path (`setSandboxMode(session, mode)`), and `SANDBOX_MODES`. The event is policy state — consumed by two families — so it lives here, not in either capability's seam. Its shape and log-only semantics match the `approval/*` precedent.
+- `defaultMode` / `workspaceRoot` accessors the enforcing implementations read for their resolve fallback and boundary.
+
+`dsh-bash-sandbox` carries no sandbox config of its own — it injects `sandboxPolicy` and reads the default from it; its `resolve()` precedence is unchanged (escalation grant > per-call stamp > default). `dsh-tool-bash` and `dsh-tool-fs` fold the session's `sandbox/mode` with `effectiveSandboxMode` to stamp each call; `dsh-permission` presets and the ACP bridge write through the relocated setter. The seam that owns bash execution no longer depends on `dsh-session` at all — the session dependency moved to the policy package with the fold.
+
+### `dsh-fs-sandbox` — enforcement inside the provider
+
+`packages/fs/fs-sandbox/` (`@deepseek-ai/dsh-fs-sandbox`) mirrors the `bash-local`/`bash-sandbox` split: `SandboxedFileSystem extends LocalFileSystem`, registered as `ctx.fs`, injecting `sandboxPolicy`. Reads (`resolve`/`stat`/`readText`/`streamText`/`listDir`) pass through untouched — every mode permits reading. The two mutations enforce by mode before delegating to the inherited atomic write:
+
+- `read-only` denies `writeText`/`editText` outright.
+- `workspace-write` fences the canonicalized target against the writable-root set — `writableRoots(policy)` in `dsh-sandbox`: the workspace root plus the platform temp areas (`/tmp`, `os.tmpdir()`), each realpathed — the SAME set the Seatbelt profile grants, so the fs fence is the fourth dialect of one mode meaning alongside the bwrap/Landlock/Seatbelt profiles, and "the write tool cannot write `/tmp` but bash can" asymmetries cannot arise. Containment is prefix-inclusion on real paths; the target is re-canonicalized (`resolve` realpaths the deepest existing ancestor) immediately before delegating, so an ancestor symlink swapped since the tool resolved it is caught.
+- `danger-full-access` delegates unfenced.
+
+A denial is the structured `FS_SANDBOX_DENIED` carrying the effective mode — distinct from `FS_PERMISSION_DENIED` (a host EACCES is the world refusing; this is policy refusing). No text inference: an in-process fence knows exactly what it denied. The per-call carrier is a trailing optional `sandboxMode` on `writeText`/`editText` (the filesystem twin of `BashExecRequest.sandboxMode`); the seam stays session-free (the caller stamps, exactly as `resolve` takes a cwd), and the bare local backend carries-and-ignores it. `FileSystem.sandboxMode` is the capability fact (`undefined` on the base and `fs-local`, the default on `SandboxedFileSystem`), so the tool layer advertises escalation from composition truth.
+
+The threat model is stated in the package README: a policy fence in trusted code over model-controlled paths, not a kernel boundary — the operations are the seam's own, only the target path is untrusted, so canonicalize-then-contain is the complete answer to this surface (the `code-runtime` "containment, not a security boundary" precedent). Kernel-grade isolation of untrusted CODE stays `ctx.bash`'s job. The residual resolve-to-syscall race is narrowed by the in-place re-canonicalization and eliminated only by platform primitives (`openat2` `RESOLVE_BENEATH`) not worth their portability cost here.
+
+### Tool parity — one denial marker, one escalation flow
+
+`dsh-tool-fs` stamps the effective mode onto each mutation and maps `FS_SANDBOX_DENIED` to the marker the model already knows from bash: `[sandbox: file access denied under <mode> mode]`. When `ctx.fs.sandboxMode` reports a confining mode at registration, `write` and `edit` advertise the same `sandbox_permissions` + `justification` fields, teach the same same-turn retry, and resolve the same `ctx.approval` request before executing — the four outcomes and their verbatim fail-closed texts carried over from [the sandbox Agent Note](2026-07-06-sandbox.md) § Escalation (strict widening checked at execution against the call's effective mode; a grant consumed by the one call that asked; no new session events).
+
+The shared pieces live in `dsh-sandbox`, which owns the mode types: `WIDER_MODES`, the escalation-target enum, the argument-pairing validation, the denial/hint marker builders, and `approveEscalation` — the ordered fail-closed choreography. `approveEscalation` takes a minimal STRUCTURAL approver (`EscalationApprover`, generic over the agent and call-id types), not the approval service type, so `dsh-sandbox` gains no dependency on the approval or agent packages: each tool passes its own `ctx.approval`, agent, call id, and tool name as ingredients. `dsh-tool-bash` and `dsh-tool-fs` both use these; the cross-file duplication gate holds the single-sourcing honest.
+
+The [`examples/acp-agent`](../../../../examples/acp-agent/cordis.yml) composition loads `dsh-sandbox-policy` and `dsh-fs-sandbox`, moves the `mode`/`workspaceRoot` config to the policy entry, and drops the old gating that disabled the fs stack under confined modes; `fs-policy` (read-before-edit) composes orthogonally on top. The system prompt still states no sandbox mode — the marker teaches the boundary at the moment it matters, per the sandbox Agent Note's live evidence.
+
+### The enforcement point: provider, not intent gate
+
+The sandbox Agent Note's original cross-family sketch put fs enforcement on the `fs/write-intent`/`fs/edit-intent` events. This Agent Note enforces in the provider instead, on two mechanical facts: the intent slots are single-decision first-wins (occupied by `dsh-fs-policy`, whose contract names a second decider a misconfiguration), and the intent events are dispatched only by `dsh-tool-fs` — a direct `ctx.fs` caller (a cordis-mounted plugin, a custom tool) bypasses them, where provider-level enforcement covers every caller by construction. The sandbox Agent Note's deferred-phase wording is updated to match in the same change.
+
+### Out of scope
+
+- **Network policy for `ctx.web`** — `SandboxMode` claims file effects only; a web-only network knob while bash `curl` runs free would be a false boundary. Revisit when a bash backend enforces network (bwrap `--unshare-net`, Landlock ABI v4+).
+- **The `subagent-acp` consumer** and **per-session workspace root** — unchanged deferred phases of the sandbox RFC; centralizing the root in `ctx.sandboxPolicy` is groundwork for the latter, not its design.
+- **A uniform per-tool sandbox runtime** — remains rejected for the reasons in the sandbox RFC.
+
+## Alternatives considered
+
+- **Enforce on the `fs/*` intent events (the sandbox Agent Note's original sketch)** — rejected on the two mechanical facts in § The enforcement point: single-slot first-wins already occupied, and a bypass for direct `ctx.fs` callers. Provider-level enforcement covers every caller and mirrors bash's swap-the-implementation shape.
+- **Enforce in `tools/pre-execute`** — rejected: the listener sees the model's raw path string before `resolve()`, so it would re-implement cwd defaulting and symlink canonicalization and still race the real resolve. Disqualifying for `workspace-write`, a judgment over canonical paths.
+- **Inline checks in `dsh-tool-fs`** — rejected: covers only the tool path (same bypass as the intent events) and duplicates resolve knowledge one layer above where the canonical target already exists.
+- **A `mode` flag on `dsh-fs-local` instead of a sibling backend** — rejected: the capability fact must be composition truth the way `dsh-bash-local` vs `dsh-bash-sandbox` is; a config flag makes the tool's advertisement conditional on configuration, and the bash family already establishes the sibling-package shape.
+- **Kernel-enforced fs mutations via a confined helper subprocess** — rejected: a process per write; `editText`'s read-match-write critical section would have to move wholesale into the child to stay atomic; and the threat surface (trusted operations, untrusted path argument) does not need a kernel — the fence in trusted code is the complete answer, while untrusted-code isolation stays on `ctx.bash`.
+- **Per-family policy config with a load-time consistency check** — rejected: two homes for one fact, patched by a check that must enumerate every future enforcing family; the policy service makes drift inexpressible instead of detected.
+- **Keep the override event in `dsh-bash` as `bash/sandbox-mode`** — rejected: the event is policy state consumed by two families; leaving it bash-named forces `dsh-fs-sandbox` to depend on bash vocabulary. Pre-release, the rename is a same-change move with snapshot re-records, no shims.
+- **Escalation choreography imported from the approval/agent packages into `dsh-sandbox`** — rejected: it would invert the layering (a base vocabulary package depending on UI/agent packages). The structural approver keeps the logic single-sourced in `dsh-sandbox` while the dependencies stay in the tool layer that already holds them.
+- **A consolidated mutation-options object on the fs seam** (the shape first sketched for the per-call carrier) — rejected on friction: it churns every `writeText`/`editText` caller and splits `signal` across an options bag for mutations while reads keep it positional. A trailing optional `sandboxMode` matches bash's carry-and-ignore pattern and keeps `signal` symmetric across the seam.
+- **Extra writable-root grants on `SandboxPolicy` now** — deferred unchanged: `writableRoots()` derives from the mode meaning today; ad-hoc grants are an escalation-scope question the sandbox RFC left open.
+
+## Consequences
+
+What shipped — the tiers in § Testing hold each:
+
+- Under `read-only`, `write`/`edit` return the `[sandbox: file access denied under read-only mode]` marker and the disk is untouched; `read`/`listDir` behave identically to `dsh-fs-local`.
+- Under `workspace-write`, mutations land under the workspace root and the temp areas and are denied outside; the containment matrix — `..` traversal, absolute paths outside, a pre-existing symlinked directory inside pointing out, and a new file created under such a symlink — denies every escape on real disks.
+- A denied fs mutation retried once with `sandbox_permissions` + `justification` prompts through the composed approval chain; a grant runs exactly that call under the wider mode and the write lands; rejected/cancelled/unavailable each produce their verbatim fail-closed text and mutate nothing.
+- One `permission` preset switch governs both families: after a session switches modes, the next bash call and the next fs mutation both honor the new mode from the same `sandbox/mode` fold.
+- A direct `ctx.fs.writeText` with no per-call stamp is confined at the deployment default.
+- The escalation fields on `write`/`edit` exist exactly when the mounted `ctx.fs` confines, absent under `dsh-fs-local`.
+- `agent-loop` is untouched — everything rides `ctx.sandboxPolicy`, the `ctx.fs` seam, `SessionEventMap` merging, and the tool-execution pipeline.
+
+Costs and accepted limits:
+
+- **The fs fence is a policy boundary, not a kernel one.** Its threat surface is model-chosen paths, not adversarial host processes; the residual resolve-to-syscall TOCTOU is narrowed, not eliminated, and the README says so. Kernel boundaries remain bash's.
+- **`dsh-bash-sandbox` gains a hard dependency on `ctx.sandboxPolicy`.** Every sandboxed composition adds one `cordis.yml` entry or fails loud at load — the intended pre-release foundation move; the examples update in the same change.
+- **Fence-vs-runner parity is derived, not asserted.** The fs fence and the Seatbelt profile both take their writable set from `writableRoots`, and a parity unit test pins the sets; a runner profile changing its writable set without that function would drift.
+- **The marker and escalation teaching now serve two families.** A wording change is a coordinated edit behind one builder in `dsh-sandbox`; the duplication gate and pinned snapshots hold it single-sourced, at the cost that fs and bash cannot deliberately diverge in phrasing without splitting the builder.
+
+## Testing
+
+- Unit: `dsh-sandbox` pins the escalation ladder, the marker builders, the argument-pairing validation, and `approveEscalation`'s ordered fail-closed sequence (non-widening, no-approval, no-agent, each outcome), plus `writableRoots`/`canonicalPath`. `dsh-sandbox-policy` pins the default accessors, the fold/setter, the load-time mode rejection, and HMR safety. `dsh-fs-sandbox` pins the per-mode fence and the containment matrix (inside, temp area, absolute-outside, `..`, symlinked-out directory, new file under one, path-equals-root, root-ending-in-separator) on a real filesystem, plus the per-call override and HMR safety. `dsh-tool-fs` pins advertisement gating, the mode stamp, the fold, denial-marker mapping, and the full escalation matrix (grant, reject, no-service, no-agent, pairing, non-confining guard). `dsh-tool-bash`, `dsh-bash-sandbox`, and `dsh-permission` migrate to the relocated policy/kit.
+- Snapshot: the acp-agent example composes `dsh-sandbox-policy` + `dsh-fs-sandbox`; the pinned header carries the fs escalation fields and the `sandbox/mode` event name, re-recorded once.

.agents/notes/implemented/feature/2026-07-14-cross-family-fs-sandbox.zh.md

@@ -0,0 +1,94 @@
+# Agent Note: 跨家族文件沙箱——统一策略归属、沙箱化 fs 提供方、fs 升级对等
+
+Status: implemented
+
+[English](2026-07-14-cross-family-fs-sandbox.md) | 中文
+
+## 问题
+
+`SandboxMode` 声明的是文件效果,但最初只有 `ctx.bash` 执行它。fs 工具(`write`/`edit`)在进程内经由 `ctx.fs` 变更宿主文件系统,那里的 OS argv 包装在机制上毫无意义——[沙箱 RFC](2026-07-06-sandbox.md) § In-process tools 记录了这一点,并把跨家族执行留作一个延后阶段,附带一个未决问题:进程内执行是各 seam 各自表达,还是变成一个统一的 harness 能力。本 Agent Note 就是那个阶段,并给出答案:一个共享的策略归属,在每个家族各自正确的高度上做 per-seam 执行。
+
+这个缺口不是 read-only 形状的。一个受限编码 agent 的产品模式是 `workspace-write`:bash 已经可以在工作区根目录下写入,而其外的一切都被拒绝,所以一个只能全部拒绝的 fs 执行会严格劣于禁用 fs 工具——模型会尝试在工作区内 `write`,被拒,然后学会绕道 `bash` heredoc。因此跨家族执行必须讲完整的模式阶梯,包括 `workspace-write` 要求的路径包含判定(规范化目标;`..`/符号链接/绝对路径逃逸),以及与 bash 相同的升级杠杆。
+
+第二个执行家族还暴露了原布局中的一个归属问题。部署默认值(`mode` + `workspaceRoot`)配置在 `dsh-bash-sandbox` 上,而 per-session 覆盖事件是 `bash/sandbox-mode`,由 `dsh-bash` 的 session-mode 工具集折叠与写入。当 fs 执行同一套策略时,要么 fs 读取 bash 的配置与事件(一个能力家族依赖同级插件的配置),要么各家族各持一份副本——两份 `workspaceRoot` 会漂移进沙箱 RFC 警告过的那个割裂世界:bash 受限于一个根,而 fs 围栏另一个根。
+
+## Decision
+
+三个相互协调的部分,全部在叶子 `cordis.yml` 中组合,均不触及 `agent-loop`。
+
+### `ctx.sandboxPolicy`——mode 与工作区根的统一归属
+
+`packages/sandbox/sandbox-policy/`(`@deepseek-ai/dsh-sandbox-policy`)注册 `ctx.sandboxPolicy`,即部署沙箱策略的唯一所有者:
+
+- `Config`:`mode`(封闭的 `SandboxMode` 联合,默认 `read-only`)与 `workspaceRoot`(默认进程 cwd,解析为绝对路径)。配置错误在加载时高声失败。
+- per-session 覆盖事件 `sandbox/mode`,连同它的纯折叠(`effectiveSandboxMode(events)`)、写入路径(`setSandboxMode(session, mode)`)与 `SANDBOX_MODES`。该事件是策略状态——被两个家族消费——所以它住在这里,而不在任一能力的 seam 里。它的形状与仅日志(log-only)语义遵循 `approval/*` 的先例。
+- `defaultMode` / `workspaceRoot` 访问器,供执行实现读取其 resolve 回退值与边界。
+
+`dsh-bash-sandbox` 自身不再携带任何沙箱配置——它注入 `sandboxPolicy` 并从中读取默认值;其 `resolve()` 优先级不变(升级授权 > per-call 盖章 > 默认)。`dsh-tool-bash` 与 `dsh-tool-fs` 用 `effectiveSandboxMode` 折叠会话的 `sandbox/mode` 以对每次调用盖章;`dsh-permission` 预设与 ACP bridge 经由迁移后的 setter 写入。拥有 bash 执行的那个 seam 不再依赖 `dsh-session`——会话依赖随折叠一起迁到了策略包。
+
+### `dsh-fs-sandbox`——在提供方内部执行
+
+`packages/fs/fs-sandbox/`(`@deepseek-ai/dsh-fs-sandbox`)镜像 `bash-local`/`bash-sandbox` 的拆分:`SandboxedFileSystem extends LocalFileSystem`,注册为 `ctx.fs`,注入 `sandboxPolicy`。读取(`resolve`/`stat`/`readText`/`streamText`/`listDir`)原样透传——每种模式都允许读。两个变更操作在委托给继承来的原子写之前按模式执行:
+
+- `read-only` 直接拒绝 `writeText`/`editText`。
+- `workspace-write` 把规范化后的目标围栏于可写根集合——`dsh-sandbox` 中的 `writableRoots(policy)`:工作区根加上平台临时目录(`/tmp`、`os.tmpdir()`),各自 realpath——与 Seatbelt profile 授予的是同一个集合,所以 fs 围栏是这一个模式含义在 bwrap/Landlock/Seatbelt profile 之外的第四种方言,因此不会出现「write 工具不能写 `/tmp` 而 bash 能」的不对称。包含判定是对真实路径的前缀包含;目标在委托前被立即重新规范化(`resolve` 对最深的既有祖先做 realpath),因此自工具解析该目标以来被换出的祖先符号链接会被捕获。
+- `danger-full-access` 不加围栏地委托。
+
+拒绝是结构化的 `FS_SANDBOX_DENIED`,携带生效模式——区别于 `FS_PERMISSION_DENIED`(宿主 EACCES 是世界在拒绝;这里是策略在拒绝)。无文本推断:进程内围栏确切知道它拒绝了什么。per-call 载体是 `writeText`/`editText` 上一个末尾可选的 `sandboxMode`(文件系统侧对应 `BashExecRequest.sandboxMode`);该 seam 保持无会话依赖(由调用方盖章,正如 `resolve` 接收一个 cwd),而裸的本地后端携带并忽略它。`FileSystem.sandboxMode` 是能力事实(在基类与 `fs-local` 上为 `undefined`,在 `SandboxedFileSystem` 上为默认值),所以工具层按组合真相来宣告升级。
+
+威胁模型写在包 README 里:一道位于可信代码中、针对模型可控路径的策略围栏,而非内核边界——操作是 seam 自身的,只有目标路径不可信,所以「先规范化再判包含」是对这个面的完整答案(`code-runtime` 的「containment, not a security boundary」先例)。对不可信代码的内核级隔离仍是 `ctx.bash` 的职责。resolve 到系统调用之间残留的竞态被就地重新规范化收窄,只有平台原语(`openat2` `RESOLVE_BENEATH`)能彻底消除它,而那在此不值其可移植性代价。
+
+### 工具对等——一个拒绝标记、一条升级流程
+
+`dsh-tool-fs` 把生效模式盖章到每次变更上,并将 `FS_SANDBOX_DENIED` 映射为模型已从 bash 认识的标记:`[sandbox: file access denied under <mode> mode]`。当 `ctx.fs.sandboxMode` 在注册时报告一个受限模式,`write` 与 `edit` 宣告相同的 `sandbox_permissions` + `justification` 字段,教授相同的同回合重试,并在执行前解析相同的 `ctx.approval` 请求——四种结果及其逐字的 fail-closed 文案沿用自[沙箱 RFC](2026-07-06-sandbox.md) § Escalation(严格加宽在执行时针对调用的生效模式检查;授权由发起它的那一次调用消费;无任何新会话事件)。
+
+共享部分住在 `dsh-sandbox`,它拥有模式类型:`WIDER_MODES`、升级目标枚举、参数配对校验、拒绝/提示标记构造器,以及 `approveEscalation`——有序的 fail-closed 编排。`approveEscalation` 接收一个最小的结构化 approver(`EscalationApprover`,对 agent 与 call-id 类型泛型化),而非审批服务类型,所以 `dsh-sandbox` 不获得对 approval 或 agent 包的依赖:每个工具把自己的 `ctx.approval`、agent、call id 与工具名作为原料传入。`dsh-tool-bash` 与 `dsh-tool-fs` 都使用它们;跨文件重复检测门禁确保单一来源不走样。
+
+[`examples/acp-agent`](../../../../examples/acp-agent/cordis.yml) 组合加载 `dsh-sandbox-policy` 与 `dsh-fs-sandbox`,把 `mode`/`workspaceRoot` 配置移到策略条目,并去掉在受限模式下禁用整个 fs 栈的旧门控;`fs-policy`(read-before-edit)正交地叠加其上。系统提示仍然不陈述沙箱模式——标记会在真正重要的那一刻教会模型边界,依据沙箱 RFC 的线上证据。
+
+### 执行点:提供方,而非 intent gate
+
+沙箱 RFC 最初的跨家族草图把 fs 执行放在 `fs/write-intent`/`fs/edit-intent` 事件上。本 Agent Note 改为在提供方中执行,基于两个机制性事实:intent 槽是单决策、先到先得(已被 `dsh-fs-policy` 占据,其契约称第二个决策者为配置错误),且 intent 事件只由 `dsh-tool-fs` 派发——一个直连 `ctx.fs` 的调用方(一个 cordis 挂载插件、一个自定义工具)会绕过它们,而提供方级执行按构造覆盖每一个调用方。沙箱 RFC 的延后阶段措辞在同一变更中被更新以匹配。
+
+### 范围之外
+
+- **`ctx.web` 的网络策略**——`SandboxMode` 只声明文件效果;在 bash `curl` 畅通时给一个仅限 web 的网络旋钮会是一道假边界。待某个 bash 后端能执行网络(bwrap `--unshare-net`、Landlock ABI v4+)时再议。
+- **`subagent-acp` 消费者** 与 **per-session 工作区根**——沙箱 RFC 未变的延后阶段;把根集中到 `ctx.sandboxPolicy` 是后者的铺垫,而非其设计。
+- **统一的 per-tool 沙箱运行时**——因沙箱 RFC 中的理由继续否决。
+
+## Alternatives considered
+
+- **在 `fs/*` intent 事件上执行(沙箱 RFC 的原始草图)**——因 § 执行点 中的两个机制性事实被否决:单槽先到先得且已被占据,以及对直连 `ctx.fs` 调用方的绕过。提供方级执行覆盖每一个调用方,并镜像 bash 的换实现形态。
+- **在 `tools/pre-execute` 中执行**——否决:监听器在 `resolve()` 之前看到模型的原始路径字符串,因此它会重新实现 cwd 默认化与符号链接规范化,并且仍与真正的 resolve 竞态。对 `workspace-write`(一个对规范路径的判定)而言是取消资格级的。
+- **在 `dsh-tool-fs` 中做内联检查**——否决:只覆盖工具路径(与 intent 事件同样的绕过),并在规范目标已存在之上重复了一层 resolve 知识。
+- **在 `dsh-fs-local` 上加一个 `mode` 标志而非同级后端**——否决:能力事实必须是组合真相,正如 `dsh-bash-local` 对 `dsh-bash-sandbox`;一个配置标志会让工具的宣告取决于配置,而 bash 家族已经确立了同级包形态。
+- **经受限 helper 子进程做内核级 fs 变更**——否决:每次写一个进程;`editText` 的读-匹配-写临界区不得不整体搬进子进程才能保持原子;而威胁面(可信操作、不可信路径参数)不需要内核——可信代码中的围栏就是完整答案,而不可信代码隔离仍在 `ctx.bash`。
+- **带加载期一致性校验的 per-family 策略配置**——否决:一个事实两个归属,靠一个必须枚举每个未来执行家族的校验来打补丁;策略服务让漂移不可表达,而非被检测到。
+- **把覆盖事件留在 `dsh-bash` 里作 `bash/sandbox-mode`**——否决:该事件是被两个家族消费的策略状态;保留 bash 命名会迫使 `dsh-fs-sandbox` 依赖 bash 词汇。预发布阶段,该改名是同一变更内的迁移,附带快照重录,无任何 shim。
+- **把升级编排从 approval/agent 包导入 `dsh-sandbox`**——否决:那会倒置分层(一个基础词汇包依赖 UI/agent 包)。结构化 approver 让逻辑单一来源于 `dsh-sandbox`,而依赖留在本就持有它们的工具层。
+- **fs seam 上一个合并的 mutation-options 对象**(per-call 载体最初草拟的形状)——因摩擦被否决:它会搅动每一个 `writeText`/`editText` 调用方,并把 `signal` 拆进变更专用的选项包,而读取仍保持位置参数。一个末尾可选的 `sandboxMode` 匹配 bash 的携带并忽略模式,并使 `signal` 在整个 seam 上保持对称。
+- **现在就在 `SandboxPolicy` 上加额外的可写根授权**——照旧延后:`writableRoots()` 如今由模式含义推导;临时授权是沙箱 RFC 留下的升级作用域问题。
+
+## Consequences
+
+已交付的部分——§ Testing 的各层各自钉住:
+
+- 在 `read-only` 下,`write`/`edit` 返回 `[sandbox: file access denied under read-only mode]` 标记,磁盘不受触动;`read`/`listDir` 与 `dsh-fs-local` 行为一致。
+- 在 `workspace-write` 下,变更落在工作区根与临时目录下,其外被拒;包含矩阵——`..` 穿越、指向外部的绝对路径、一个既有的、指向外部的工作区内符号链接目录,以及在这样一个符号链接下新建的文件——在真实磁盘上拒绝每一种逃逸。
+- 一个被拒的 fs 变更,携带 `sandbox_permissions` + `justification` 重试一次,会经组合的审批链提示;一次授权让恰好那一次调用在更宽的模式下运行且写入落盘;rejected/cancelled/unavailable 各自产生其逐字的 fail-closed 文案且不做任何变更。
+- 一次 `permission` 预设切换同时管辖两个家族:会话切换模式后,下一次 bash 调用与下一次 fs 变更都从同一个 `sandbox/mode` 折叠遵循新模式。
+- 一次无 per-call 盖章的直连 `ctx.fs.writeText` 会被围栏于部署默认值。
+- `write`/`edit` 上的升级字段恰好在被挂载的 `ctx.fs` 受限时存在,在 `dsh-fs-local` 下不存在。
+- `agent-loop` 未被触动——一切都骑在 `ctx.sandboxPolicy`、`ctx.fs` seam、`SessionEventMap` 合并,以及工具执行管线之上。
+
+代价与接受的限制:
+
+- **fs 围栏是策略边界,而非内核边界。** 它的威胁面是模型选定的路径,而非对抗性宿主进程;resolve 到系统调用之间残留的 TOCTOU 被收窄而非消除,README 已如实声明。内核边界仍属 bash。
+- **`dsh-bash-sandbox` 获得对 `ctx.sandboxPolicy` 的硬依赖。** 每个沙箱化组合要么加一个 `cordis.yml` 条目,要么在加载时高声失败——这是有意的预发布奠基之举;示例在同一变更内更新。
+- **围栏与 runner 的对等是推导出来的,而非断言的。** fs 围栏与 Seatbelt profile 都从 `writableRoots` 取其可写集合,一个对等单元测试钉住这些集合;一个 runner profile 若在不经该函数的情况下改变其可写集合便会漂移。
+- **标记与升级教学如今服务于两个家族。** 措辞改动是 `dsh-sandbox` 中一个构造器背后的协调编辑;重复检测门禁与钉住的快照维持单一来源,代价是 fs 与 bash 无法在不拆分该构造器的情况下有意地在措辞上分道。
+
+## Testing
+
+- 单元:`dsh-sandbox` 钉住升级阶梯、标记构造器、参数配对校验,以及 `approveEscalation` 的有序 fail-closed 序列(非加宽、无 approval、无 agent、各结果),外加 `writableRoots`/`canonicalPath`。`dsh-sandbox-policy` 钉住默认访问器、折叠/setter、加载期模式拒绝,以及 HMR 安全。`dsh-fs-sandbox` 在真实文件系统上钉住 per-mode 围栏与包含矩阵(内部、临时目录、绝对路径-外部、`..`、指向外部的符号链接目录、其下的新建文件、路径等于根、以分隔符结尾的根),外加 per-call 覆盖与 HMR 安全。`dsh-tool-fs` 钉住宣告门控、模式盖章、折叠、拒绝标记映射,以及完整的升级矩阵(授权、拒绝、无服务、无 agent、配对、非受限守卫)。`dsh-tool-bash`、`dsh-bash-sandbox` 与 `dsh-permission` 迁移到迁移后的策略/工具集。
+- 快照:acp-agent 示例组合 `dsh-sandbox-policy` + `dsh-fs-sandbox`;被钉住的 header 携带 fs 升级字段与 `sandbox/mode` 事件名,一次性重录。