docs: tighten prose audit after master retarget

packages/bash/bash-local/README.md

@@ -22,7 +22,7 @@ Design surveyed against the bash tools of Claude Code, OpenCode, Codex, and pi;
 - **Spawn per call, no shell state** — every call is a fresh non-login `bash -c` (deterministic; no rc files). All four surveyed tools spawn per call. `XXX(stateful-shell)` in `src/run.ts` records the two proven stateful designs (Claude Code's cwd-only persistence; Codex's PTY exec sessions) for when real workflows demand them.
 - **Process-group kills with escalation** — children are spawned `detached` (own process group); kills send SIGTERM to the group, then SIGKILL after the `graceMs` grace (default 3s — OpenCode's escalation; pipelines and subshells die with the parent). ESRCH is tolerated; daemons that re-parent away from the group can still survive — same caveat as the surveyed tools.
 - **Tail-keep truncation + spill files** — output beyond `maxOutputBytes` keeps the in-memory TAIL (errors/results cluster at the end — pi/OpenCode rationale) while the FULL stream is appended to a temp file whose path is reported when available. If the final spill close reports a delayed writeback failure, the executor still returns the tail but withholds the path rather than advertising a possibly incomplete file.
-- **Model-friendly env + credential scrub** — `process.env` minus credential-shaped vars (`*KEY*`/`*SECRET*`/`*TOKEN*`), then `NO_COLOR=1 TERM=dumb PAGER=cat GIT_PAGER=cat` (Codex's hardcoded set) so pagers and ANSI color don't garble results. This scrub is the security control that keeps the harness's *ambient* credentials out of a spawned command. A spec's `env` is merged LAST (after the scrub), so a caller's explicit entry — a value it already holds — wins even on a credential-shaped name. The spec's `stdin`, when supplied, is written to the child and closed; with none supplied, fd 0 is `/dev/null` — the exact pre-seam default, so a command that probes stdin's file type is unaffected. Both `env`/`stdin` are set by in-process plugins (the hooks bridges); the model-facing tool doesn't expose them. See [the bash-stdin-env RFC](../../../docs/rfc/implemented/architecture/2026-06-30-bash-stdin-env-trusted-plugin-surface.md).
+- **Model-friendly environment** — ambient credential-shaped variables are removed before noninteractive terminal defaults and explicit caller entries are applied. Supplied stdin is written and closed; otherwise fd 0 is `/dev/null`. Trusted plugins use `env` and `stdin`, but the model-facing tool does not expose them. See the [bash stdin/env RFC](../../../docs/rfc/implemented/architecture/2026-06-30-bash-stdin-env-trusted-plugin-surface.md).
 - **Background tasks** — `start()` returns immediately, no timeout applies (Claude Code detaches timeouts when backgrounding), `readOutput()` is incremental with whole-stream byte offsets, and disposal kills everything. The spec's opaque `owner` token is stored on the tracked task and returned by `ownerOf(id)` — the executor never interprets it (the consumer's access policy does), and because it lives with the task here it survives a `tool-bash` HMR reload.
 
 ## Sandboxing

packages/bash/bash-sandbox/README.md

@@ -14,7 +14,7 @@ Semantics:
 
 - **Denials are result facts.** A failed run whose stderr carries the selected backend's own denial dialect — the signatures the provider stamps on every wrap (EROFS text under bwrap, EACCES under Landlock, EPERM under Seatbelt) — is reported as `BashRunResult.sandbox.denied: true` (conservative classification, read from the collected stderr tail); every CONFINED run also carries the mode it executed under (`result.sandbox.mode`) and the provider's enforcement completeness (`result.sandbox.enforcement`: `full`, or `partial` on an older Landlock ABI).
 - **Runner failures are sandbox failures, never task failures.** A failed run matching the wrap's `runnerFailureSignatures` (the runner's own error prefix — also what the shell prints for a missing runner) means the sandbox itself broke and the command NEVER RAN; the check outranks denial classification because a runner's error text can contain denial words. The foreground path re-throws it as the structured fail-closed `SANDBOX_UNAVAILABLE` error, with the runner's first stderr line as the cause; a settled background task stamps `task.sandbox.runnerFailed` instead (no error channel remains after settle), which `bash_output` renders as its own marker.
-- **Config-time default, per-call policy.** The DEFAULT mode is fixed by this entry's config for the executor's lifetime; `resolve()` stamps it onto every spec, and an explicit request-level `sandboxMode` override — set by the tool layer only for a call whose wider mode a human granted through `ctx.approval` ([the sandbox RFC § Escalation](../../../docs/rfc/implemented/feature/2026-07-06-sandbox.md)) — makes THAT call run, classify, and report under its own mode while every neighbor keeps the default (background facts are stamped per task at settle). The capability fact `ctx.bash.sandboxMode` reports the configured default so the tool layer advertises escalation only when this executor is mounted. The model learns of the sandbox only through result facts — the static bash tool description explains the denial marker; there is no current-mode statement in the system prompt.
+- **Config default, per-call override.** `resolve()` stamps the configured sandbox mode onto each spec unless an approved request supplies a wider mode. That override affects only its call or background task. `ctx.bash.sandboxMode` reports the default so the tool advertises escalation only when supported; results report the effective mode.
 - **File effects only.** Network and process visibility are deliberately not restricted — the mode vocabulary does not pretend to cover what the backend does not enforce.
 - Process mechanics (spawn, process-group kills, output collection/spill, background tasks, credential scrub) are inherited verbatim from [`dsh-bash-local`](../bash-local/); the runner ladder, probes, and the per-platform Landlock launcher packages live with [`dsh-sandbox-local`](../../sandbox/sandbox-local/).
 

packages/bash/bash-sandbox/tests/seatbelt.e2e.ts

@@ -9,16 +9,8 @@ import { LocalSandboxProvider, seatbeltProfileArgs } from '@deepseek-ai/dsh-sand
 import { SandboxBashExecutor } from '@deepseek-ai/dsh-bash-sandbox'
 
 /**
- * KEYLESS consumer-integration proof on macOS: the REAL `LocalSandboxProvider`
- * (Linux rungs forced off, so `sandbox-exec`/Seatbelt confines) underneath
- * the REAL `SandboxBashExecutor`, driven through the executor's public
- * run/start paths. Verifies the WORLD (files exist or don't) plus the
- * stamped result facts — in particular that Seatbelt's EPERM denial text
- * classifies as `denied: true` through the wrap-carried dialect; the
- * backend-only confinement proofs live with `@deepseek-ai/dsh-sandbox-local`.
- *
- * Self-skips wherever the functional probe fails — every non-macOS host, or
- * a macOS whose `sandbox-exec` refuses the profile.
+ * Keyless macOS integration of the real Seatbelt provider and sandbox executor,
+ * including world effects and denial classification. Skips when the probe fails.
  */
 
 const probe = spawnSync('sandbox-exec', [...seatbeltProfileArgs({ mode: 'read-only', workspaceRoot: '/' }), '--', 'true'], { timeout: 5_000, stdio: 'ignore' })

packages/bash/bash/src/index.ts

@@ -60,12 +60,7 @@ export abstract class BashExecutor extends Service {
   }
 
   /**
-   * Resolve a caller's {@link BashExecRequest} into a fully-specified
-   * {@link BashExecSpec}, applying this implementation's config defaults and
-   * caps (working directory, default/max timeout). Consumers (tool layer)
-   * call this, then pass the result to {@link run}/{@link start} — keeping
-   * defaulting in the implementation that owns the config while the seam type
-   * stays explicit (no hidden `?? default` inside run/start).
+   * Apply implementation-owned defaults and caps to a request before execution.
    * @param request - the caller's request; omitted fields get this
    *   implementation's defaults, capped fields are clamped.
    * @returns the fully-specified spec to hand to {@link run}/{@link start}.

packages/bash/bash/src/types.ts

@@ -71,14 +71,8 @@ export interface BashSandboxInfo {
    */
   enforcement?: SandboxEnforcement
   /**
-   * True when the executor classifies this failure as the SANDBOX RUNNER
-   * itself failing (missing binary, refused profile, fail-closed refusal
-   * before exec) — the command NEVER RAN; this is a sandbox failure, not a
-   * task failure, and it outranks `denied` (a runner's own error text can
-   * contain denial words). Only ever stamped on settled BACKGROUND tasks: a
-   * foreground run surfaces the same condition as the thrown
-   * `SANDBOX_UNAVAILABLE` error instead (the foreground path has an error
-   * channel; a settled task's facts are its only channel).
+   * The sandbox runner failed before executing the command. Set only on settled
+   * background tasks; foreground runs throw `SANDBOX_UNAVAILABLE` instead.
    */
   runnerFailed?: boolean
 }

packages/bash/tool-bash/README.md

@@ -22,7 +22,7 @@ The plugin also contributes the `tool:bash` prompt section (order 105) — the c
 
 `command`, `workdir`, and `timeoutMs` are resolved against the executor's config defaults via `ctx.bash.resolve()` before execution, so the executor seam (`BashExecSpec`) receives explicit `workdir`/`timeoutMs` values. The workdir default is applied in the tool layer (from the calling agent's `session.header.cwd`) BEFORE `resolve()` — the per-session cwd must come from `exec.agent`, since N sessions share one executor; only when no session cwd is available does the executor fall back to its own config / `process.cwd()`.
 
-Result text: stdout, then a `[stderr]` section, then status markers — `[sandbox: file access denied under <mode> mode]` when a sandboxing executor classified the failure as a policy denial (reported first so `[exit code: N]` stays the last line; the static description tells the model a denial is policy, not a command bug, and forbids retrying around it), `[timed out after Nms]` whenever the executor's timer fired (reported independently of how the process ended, so a command that traps SIGTERM and exits 0 still shows it), `[killed by signal: …]` for a signal death, `[exit code: N]` for a non-zero exit (reported, **not** `isError`: the model decides how to react), and `[output truncated; full output: <path>]` when the tail was kept and a safe spill file is available. If the executor knows output was dropped but cannot safely advertise a complete spill file, the path is reported as `(unavailable)`. Only infrastructure failures (spawn errors, aborts) surface as `isError` results.
+Result text contains stdout, an optional `[stderr]` section, then applicable sandbox-denial, timeout, signal, exit-code, and truncation markers. Timeout is reported independently of final exit status; nonzero exit remains a model-interpreted result rather than `isError`. Truncation links a safe complete spill file or reports it unavailable. Only infrastructure failures such as spawn errors and aborts produce `isError`.
 
 ### `bash_output`
 
@@ -34,7 +34,7 @@ Result text: stdout, then a `[stderr]` section, then status markers — `[sandbo
 
 ### Task ownership (cross-session isolation)
 
-The owning agent's session token (`session.header.id`) is stamped onto the task at spawn — passed to the executor via `resolve({ …, owner })` and stored ON THE TASK inside the executor (the `dsh-bash` `ownerOf(id)` seam), **not** in a plugin-local map. `bash_output`/`bash_kill` compare `ctx.bash.ownerOf(id)` to the caller's token (`session.header.id`) with `!== undefined` semantics and reject a task owned by a *different* session with `task <id> belongs to another session` (a task started with no agent — a non-loop caller — has no owner token and is open to anyone; a call with no `exec.agent` cannot access an owned task). Task ids are global and predictable, so under multi-session ACP this token check is the fence that stops one session's agent from reading or killing another session's background task. Because ownership lives on the task in the executor (disposed with the `dsh-bash` fiber), it **survives an independent `tool-bash` HMR reload** — closing the old plugin-local-map gap where a reload orphaned pre-reload tasks. (The `onTaskDone` listener is still effect-scoped to this plugin's `apply`, so a completion landing during the reload gap still drops its one notice — the pre-existing reload-gap drop — but the ownership fence itself is HMR-proof.)
+The executor stores the spawning session id as the task's owner. `bash_output` and `bash_kill` reject a caller with a different session id; agent-less tasks remain unowned, while agent-less calls cannot access owned tasks. Storing ownership on the task prevents predictable global ids from crossing ACP sessions and preserves the fence across tool-plugin reloads. Completion notices remain effect-scoped and may be missed during a reload gap.
 
 ## UI presentation
 
@@ -42,11 +42,11 @@ UI presentation is tool-owned through `presentCall` and `presentResult`. Foregro
 
 ## Background completion notices
 
-When a background task finishes, a short notice is injected into the owning agent's session (`agent.inject()`, source `{kind: 'plugin', plugin: 'tool-bash'}`). The owning agent is found by its session token: the listener reads `ctx.bash.ownerOf(task.id)` and scans `ctx.get('agents')?.list()` for an agent whose `session.header.id` matches (read via `ctx.get` — `onTaskDone` runs on the bash fiber, a foreign fiber, so the `ctx.agents` proxy would throw). If no live agent carries that token — e.g. the owning session disconnected and its agent was disposed while the task ran on — the notice is dropped cleanly. Injection is **durable context for the next model request, not a wake-up** — an idle agent stays idle until something sends a message. That's why the tool descriptions tell the model to poll with `bash_output`.
+When a task finishes, the plugin resolves its owner token to a live agent and injects a durable completion notice. If the owner no longer exists, the notice is dropped. Injection affects the next request but does not wake an idle agent, so the model must poll with `bash_output` when it needs completion promptly.
 
 ## The tool builds its request from named args only
 
-The `BashExecRequest` seam carries optional `stdin` and `env`, used by the hooks bridges to feed a hook command its JSON payload and `CLAUDE_*` env. This tool does **not** expose them as parameters: its request is built from `command`/`workdir`/`timeoutMs`/`signal`/`owner` only, so a model that includes `env` or `stdin` keys in its tool arguments has them ignored. This is not a trust boundary — a model already has equivalent power through shell syntax (`FOO=bar cmd`, a heredoc), and the real defense against leaking the harness's ambient secrets is `dsh-bash-local`'s credential scrub, which works regardless. A regression guard drives the real tool with those extra args and asserts the resulting request carries neither field — its job is to catch a future refactor that blindly spreads `...args` into the request (which would silently forward model input into the post-scrub `env` merge), not to defend a wall. See [the bash-stdin-env RFC](../../../docs/rfc/implemented/architecture/2026-06-30-bash-stdin-env-trusted-plugin-surface.md).
+The seam supports trusted-plugin `stdin` and `env`, but the model-facing tool does not. It builds requests only from its declared arguments, signal, and owner; extra model keys are ignored. Shell syntax already provides equivalent command-level behavior, while the local executor's credential scrub protects ambient secrets. See the [stdin/env RFC](../../../docs/rfc/implemented/architecture/2026-06-30-bash-stdin-env-trusted-plugin-surface.md).
 
 ## Permissions and escalation
 
@@ -56,4 +56,4 @@ Escalating bash calls resolve `ctx.approval` before execution. `allowed-once` ap
 
 ## Per-session mode switching
 
-Under a sandboxing executor this plugin makes the session's standing mode override ([the sandbox RFC § Per-session mode switching](../../../docs/rfc/implemented/feature/2026-07-06-sandbox.md); the `bash/sandbox-mode` fold owned by [`dsh-bash`](../bash/README.md)) real at EXECUTION: every call is stamped `escalation grant > session override > undefined` onto `BashExecRequest.sandboxMode`; without either, the executor's `resolve()` applies its configured default. Nothing is stamped under a non-sandboxing executor (nothing would honor it) or for an agent-less caller (no session to fold). The prompt deliberately does NOT state the mode and a switch is not narrated: a standing declaration teaches the model to refuse preemptively, while the denial marker already names the mode the command ran under exactly when the boundary is hit — behavior, not belief, carries the state.
+For sandboxing executors, each call resolves mode as one-shot escalation, then session override, then executor default. Non-sandboxing and agent-less calls carry no session override. The prompt does not announce the standing mode; denial results report the effective mode when the boundary matters. See the [sandbox switching contract](../../../docs/rfc/implemented/feature/2026-07-06-sandbox.md).