feat(sandbox): Windows ACL write-restriction sandbox (restricted-token runner)

Confine Windows command execution through a WRITE_RESTRICTED token whose restricting SIDs carry an orphan-SID write allowlist, ported from https://github.com/huoyaoyuan/windows-acl-restrict-poc (@ 10e4dfb). Every Win32 call is checked and fails closed - the POC silently ran children with the FULL token when CreateRestrictedToken failed.

- @deepseek-ai/dsh-sandbox-windows-acl: koffi primitives verified against the MinGW Windows headers (verify/abi-probe.cpp) plus the confinement runner ([node, runner, --workspace, --temp, --mode, --, argv...]: kill-on-close job, stdio passthrough, exit-code mirroring, windows-acl-run: failure signature, grant revocation). read-only = strict zero grants (NUL device not writable; documented). Windows-only execution: exempted from the Linux coverage lane (windowsOnlyCoverageExclusions).
- @deepseek-ai/dsh-sandbox-local: PLATFORM_CHAINS.win32 filled with the windows-acl runner (full enforcement, ACL denial dialect, runner-failure rules).
- @deepseek-ai/dsh-pwsh-sandbox: sandbox-consuming pwsh executor (call-for-call mirror of dsh-bash-sandbox) over a new argv-level seam in dsh-pwsh-local; per-file coverage complete via the fake-provider spec.
- bundle/base: the Windows platform layer mounts the confined pwsh roster - sandbox/policy/fs-sandbox/permission/approval re-enabled, the POSIX bash stack stays disabled.

Co-authored-by: Huo Yaoyuan <huoyaoyuan@hotmail.com>

packages/bash/pwsh-local/src/index.ts

@@ -162,12 +162,27 @@ export class PwshLocalExecutor extends BashExecutor {
     }
   }
 
-  /** Map one resolved bash spec onto a fully-specified subprocess spawn. */
-  private spawnSpec(spec: BashExecSpec, stdoutMaxBytes: number, signal: AbortSignal | undefined): SubprocessSpawnSpec {
+  /**
+   * The pwsh invocation argv for one resolved spec — the argv-level seam a
+   * confining subclass wraps through `ctx.sandbox.confine` (the pwsh twin of
+   * `dsh-bash-local`'s `runArgv`/`startArgv` hooks; see
+   * `@deepseek-ai/dsh-pwsh-sandbox`).
+   */
+  protected argv(spec: BashExecSpec): string[] {
+    return [this.pwshPath, '-NoLogo', '-NoProfile', '-NonInteractive', '-Command', `${ENCODING_PREAMBLE}${spec.command}`]
+  }
+
+  /** Map one resolved spec plus its argv onto a fully-specified subprocess spawn. */
+  private spawnSpec(
+    spec: BashExecSpec,
+    stdoutMaxBytes: number,
+    signal: AbortSignal | undefined,
+    argv: readonly string[],
+  ): SubprocessSpawnSpec {
     const collect = (maxBytes: number): SubprocessCollect =>
       ({ maxBytes, spill: { maxBytes: this.config.maxSpillBytes } })
     return {
-      argv: [this.pwshPath, '-NoLogo', '-NoProfile', '-NonInteractive', '-Command', `${ENCODING_PREAMBLE}${spec.command}`],
+      argv: [...argv],
       cwd: spec.workdir,
       stdio: {
         stdin: spec.stdin !== undefined ? { data: spec.stdin } : 'ignore',
@@ -192,9 +207,14 @@ export class PwshLocalExecutor extends BashExecutor {
   }
 
   async run(spec: BashExecSpec): Promise<BashRunResult> {
+    return this.runArgv(spec, this.argv(spec))
+  }
+
+  /** Foreground run of an exact argv (the confining subclass re-wraps it). */
+  protected async runArgv(spec: BashExecSpec, argv: readonly string[]): Promise<BashRunResult> {
     // One deadline combines timeout and upstream cancellation; disposal clears its timer.
     using d = deadline(spec.signal, spec.timeoutMs, 'BASH_TIMEOUT')
-    const handle = this.ctx.subprocess.spawn(this.spawnSpec(spec, spec.stdoutMaxBytes, d.signal))
+    const handle = this.ctx.subprocess.spawn(this.spawnSpec(spec, spec.stdoutMaxBytes, d.signal, argv))
     const outcome = await handle.done
     const collected = PwshLocalExecutor.collected(handle)
     // Only this executor's timeout reason counts as timedOut; outer deadlines count as aborts.
@@ -211,8 +231,13 @@ export class PwshLocalExecutor extends BashExecutor {
   }
 
   start(spec: BashExecSpec): BashProcess {
+    return this.startArgv(spec, this.argv(spec))
+  }
+
+  /** Background start of an exact argv (the confining subclass re-wraps it). */
+  protected startArgv(spec: BashExecSpec, argv: readonly string[]): BashProcess {
     // Background runs ignore timeoutMs; callers stop them through kill() or spec.signal.
-    const running = this.ctx.subprocess.spawn(this.spawnSpec(spec, this.config.maxOutputBytes, spec.signal))
+    const running = this.ctx.subprocess.spawn(this.spawnSpec(spec, this.config.maxOutputBytes, spec.signal, argv))
     const collected = PwshLocalExecutor.collected(running)
 
     // A spawn failure produces no process output, so the subprocess service has nothing
@@ -237,12 +262,12 @@ export class PwshLocalExecutor extends BashExecutor {
         }
         proc.exitCode = outcome.exitCode
         proc.signal = outcome.signal
-        this.onProcessDone(proc, collected.stderr.readFrom(0).text)
+        this.onProcessDone(proc, collected.stderr.readFrom(0).text, false)
       }, (error: unknown) => {
         // Background spawn failures settle as killed and surface through the read path.
         proc.status = 'killed'
         spawnFailureNote = `spawn failed: ${String(error)}`
-        this.onProcessDone(proc, spawnFailureNote)
+        this.onProcessDone(proc, spawnFailureNote, true, error)
       }),
       readOutput: (): BashProcessRead => {
         const out = collected.stdout.readFrom(stdoutOffset)
@@ -278,13 +303,14 @@ export class PwshLocalExecutor extends BashExecutor {
   /**
    * Settlement hook for subclasses that attach execution facts to a process.
    * The base implementation is intentionally empty. Mirrored from
-   * `dsh-bash-local` (whose sandboxing subclass consumes the same hook); it is
-   * the declared seam for a future pwsh-confining subclass and has no consumer
-   * in this package yet.
+   * `dsh-bash-local` (whose sandboxing subclass consumes the same hook); the
+   * pwsh-confining consumer is `@deepseek-ai/dsh-pwsh-sandbox`.
    * @param _proc - the settled process handle.
    * @param _stderr - the process's retained stderr tail used by subclasses for settlement classification.
+   * @param _spawnFailed - whether the spawn rejected before any process existed.
+   * @param _spawnError - the spawn rejection, when `_spawnFailed`.
    */
-  protected onProcessDone(_proc: BashProcess, _stderr: string): void {}
+  protected onProcessDone(_proc: BashProcess, _stderr: string, _spawnFailed: boolean, _spawnError?: unknown): void {}
 }
 /* jscpd:ignore-end */