refactor(bash): centralize managed env prefix

packages/bash/bash/README.md

@@ -34,4 +34,4 @@ Implementations subclass `BashExecutor`, implement the abstract methods, and cal
 
 The seam also owns the per-session mode override vocabulary (the sandbox RFC § Per-session mode switching): the log-only `'bash/sandbox-mode'` session event, the pure fold `effectiveSandboxMode(events)` (last event wins; `undefined` means "apply the executor default"), and THE write path `setSandboxMode(session, mode)` — the session log is the store, so an override survives restart by replay and two sessions can never see each other's mode. Writers must respect turn-enclosure: the ACP bridge anchors an idle switch at the next turn rather than appending between turns. The task id (`BashTaskId`) and the `owner` token (`OwnerToken`) are [branded](../../util/brand) — `OwnerToken` is a DISTINCT brand from `SessionId` (the seam never imports `dsh-session`; the `dsh-tool-bash` consumer is the single boundary that casts its `SessionId` into one). `run()` returns `BashRunResult` (exitCode, signal, timedOut, aborted, timeoutMs, stdout/stderr as `CollectedOutput`) and `start()`/`readOutput()` use `BashTask`/`BashTaskRead` for the background side. A sandboxing executor additionally stamps `sandbox` result facts on results and settled tasks (`BashSandboxInfo`: the mode it executed under, the conservative `denied` classification, and — for confined modes — the backend's `enforcement` completeness); the mode/enforcement vocabulary is owned by the [`dsh-sandbox`](../../sandbox/sandbox/) seam, and the facts are documented in [core-data-structures/bash.md](../../../docs/core-data-structures/bash.md). See `src/types.ts` for the full contracts.
 
-`stdin` and ordinary `env` are set by in-process plugins (the hooks bridges, native plugins) to feed a hook command its JSON payload and `CLAUDE_PROJECT_DIR`/`CLAUDE_PLUGIN_ROOT` values. `dshEnv` is a separate trusted overlay restricted by type to `DSH_*` keys; model bash uses it for the current snapshot collected by `ctx.bashEnv`. Implementations remove inherited `DSH_*`, reject those names in ordinary `env`, then merge `dshEnv`, so an omitted current fact cannot fall back to stale ambient state. The model-facing tool exposes none of these as parameters. All three remain optional on the resolved spec; absent means no input/overlay. See [the bash-stdin-env RFC](../../../docs/rfc/implemented/architecture/2026-06-30-bash-stdin-env-trusted-plugin-surface.md) and [the session environment RFC](../../../docs/rfc/implemented/feature/2026-07-10-agent-session-identity-and-log-location.md).
+`stdin` and ordinary `env` are set by in-process plugins (the hooks bridges, native plugins) to feed a hook command its JSON payload and `CLAUDE_PROJECT_DIR`/`CLAUDE_PLUGIN_ROOT` values. `dshEnv` is a separate trusted overlay restricted by type to managed keys; the exported `DSH_ENV_PREFIX` is the single source for that namespace, its `DshEnvironmentKey` template type, executor scrubbing, registry validation, derived built-in names, and model guidance. Model bash uses the current snapshot collected by `ctx.bashEnv`. Implementations remove inherited managed keys, reject those names in ordinary `env`, then merge `dshEnv`, so an omitted current fact cannot fall back to stale ambient state. The model-facing tool exposes none of these as parameters. All three remain optional on the resolved spec; absent means no input/overlay. See [the bash-stdin-env RFC](../../../docs/rfc/implemented/architecture/2026-06-30-bash-stdin-env-trusted-plugin-surface.md) and [the session environment RFC](../../../docs/rfc/implemented/feature/2026-07-10-agent-session-identity-and-log-location.md).

packages/bash/bash/src/index.ts

@@ -18,7 +18,7 @@ import { Context, Service } from 'cordis'
 import type { SandboxMode } from '@deepseek-ai/dsh-sandbox'
 import type { BashExecRequest, BashExecSpec, BashRunResult, BashTask, BashTaskId, BashTaskListener, BashTaskRead, OwnerToken } from './types.ts'
 
-export { BashTaskId, OwnerToken } from './types.ts'
+export { BashTaskId, DSH_ENV_PREFIX, OwnerToken } from './types.ts'
 export { SANDBOX_MODES, effectiveSandboxMode, setSandboxMode } from './session-mode.ts'
 export type {
   BashExecRequest,
@@ -31,6 +31,7 @@ export type {
   BashTaskStatus,
   CollectedOutput,
   DshEnvironment,
+  DshEnvironmentKey,
 } from './types.ts'
 
 declare module 'cordis' {

packages/bash/bash/src/types.ts

@@ -12,8 +12,14 @@ import type { SandboxEnforcement, SandboxMode } from '@deepseek-ai/dsh-sandbox'
 /** Identifies one background task within an executor (generated `bash-N`). */
 export type BashTaskId = Branded<'BashTaskId'>
 
+/** Namespace prefix reserved for DeepSeek Harness-managed child environment facts. */
+export const DSH_ENV_PREFIX = 'DSH_' as const
+
+/** One environment key inside the managed {@link DSH_ENV_PREFIX} namespace. */
+export type DshEnvironmentKey = `${typeof DSH_ENV_PREFIX}${string}`
+
 /** Trusted DeepSeek Harness variables for one bash execution. */
-export type DshEnvironment = Readonly<Record<`DSH_${string}`, string>>
+export type DshEnvironment = Readonly<Record<DshEnvironmentKey, string>>
 
 /**
  * Brand a string as a {@link BashTaskId}.