feat(pwsh): add the pwsh-local executor and the pwsh tool

Windows-native execution foundation: PwshLocalExecutor implements the bash
executor seam over ctx.subprocess (pwsh -NoLogo -NoProfile -NonInteractive
-Command, one argv element, no quoting layer; resolvePwshPath probes
PowerShell 7 / PATH / Windows PowerShell 5.1 as a pure function), and
tool-pwsh is the minimal PowerShell-dialect model-facing tool over ctx.bash
(foreground only, managed DSH_* env, timeout/signal/exit markers, terminal
and generic presenters). Both packages carry full suites (real pwsh,
self-skipping without it) at per-file 100% coverage; vitest's Windows
exclusion narrows from packages/bash/* to the bash-requiring packages so the
pwsh suites run natively on Windows too. The CLI gains the workspace deps
and tsconfig projects without mounting either plugin; the Windows-default
roadmap is recorded as a proposed Agent Note.

docs/config-catalog.md

@@ -963,6 +963,36 @@ export interface Config {
 
 Source: [`packages/pty/pty-local/src/config.ts:6`](../packages/pty/pty-local/src/config.ts)
 
+## `@deepseek-ai/dsh-pwsh-local`
+
+Requires: `subprocess`
+
+```ts config-catalog
+/** Plugin config (all optional — `static Config` supplies the defaults). */
+export interface Config {
+  /** Default working directory for commands (default: process.cwd()). */
+  cwd?: string
+  /** Default foreground timeout in milliseconds. */
+  timeoutMs?: number
+  /** Upper bound for per-call timeout overrides. */
+  maxTimeoutMs?: number
+  /** Per-stream in-memory output cap; overflow spills to a temp file. */
+  maxOutputBytes?: number
+  /** Per-stream spill-file cap; larger streams retain only their in-memory tail. */
+  maxSpillBytes?: number
+  /** Grace period for kill escalation and for inherited pipes after shell exit. */
+  graceMs?: number
+  /**
+   * Explicit pwsh executable. When omitted, well-known Windows install
+   * locations are probed first (PowerShell 7, then Windows PowerShell 5.1),
+   * falling back to a bare `pwsh` resolved through PATH.
+   */
+  pwshPath?: string
+}
+```
+
+Source: [`packages/bash/pwsh-local/src/index.ts:43`](../packages/bash/pwsh-local/src/index.ts)
+
 ## `@deepseek-ai/dsh-repeat-tool-guard`
 
 ```ts config-catalog
@@ -1788,6 +1818,20 @@ export interface Config {
 
 Source: [`packages/pty/tool-pty/src/index.ts:35`](../packages/pty/tool-pty/src/index.ts)
 
+## `@deepseek-ai/dsh-tool-pwsh`
+
+Requires: `tools` · `bash` · `systemPrompt`
+
+```ts config-catalog
+/** Plugin config (currently empty; kept as a schema so deployments can grow it). */
+export interface Config {
+  /** DeepSeek Harness home directory exposed as `DSH_HOME`; defaults to `$DSH_HOME` or `~/.dsh`. */
+  dshHome?: string
+}
+```
+
+Source: [`packages/bash/tool-pwsh/src/index.ts:31`](../packages/bash/tool-pwsh/src/index.ts)
+
 ## `@deepseek-ai/dsh-tool-ralph`
 
 Requires: `tools` · `workflows` · `subagents` · `systemPrompt`