fix(coverage): probe the pwsh exemption with the executor's own resolution

The review caught the pwshCoverageExclusions comment claiming the inverse of
the code's behavior: a bare-PATH probe FAILING grants the exemption, so a
win32 host where only install-location pwsh (or 5.1) resolves kept the
exemption while its suites ran - over-exempting, never tightening.

resolvePwshPath/candidatePwshPaths move to the dependency-free
pwsh-local/src/resolve.ts (index.ts re-exports; public API unchanged) and
vitest.config.ts probes with that shared definition, so the exemption is
active exactly when the suites skip. The two spec headers stop saying
'on PATH' for a probe that is deliberately not PATH-only, and the parity
note records the abort backport as the one both-ways parity change (both
languages, pairing re-recorded); catalogs regenerated for the line shift.

.agents/notes/implemented/feature/2026-08-02-pwsh-tool-bash-parity.zh.md

@@ -26,7 +26,8 @@ Status: implemented
 
 ## 后果
 
-- bash 与 pwsh 工具在前台与后台 shell 工作（减 sandbox）上行为可互换，pwsh 的 prompt/描述句每句都有渲染器背书——reviewer 的"拿代码 grep 对证"检查通过。
+- bash 与 pwsh 工具在前台与后台 shell 工作（减 sandbox）上行为可互换，pwsh 的 prompt/描述句每句都有渲染器背书——reviewer 的“拿代码 grep 对证”检查通过。
+- 对齐也反向发生过一次：pwsh 工具的结构化前台中止（`HarnessError('tool call aborted', TOOL_ABORTED)`，name 为 `AbortError`）被回移到 bash 工具，取代其无码的 `Error('command aborted')`——这是模型可见/入日志的变更，由两侧的精确形状测试与 cancel-tool-calls fixture 钉住。
 - `@deepseek-ai/dsh-bash-env` 成为新的交付包；`dsh-tool-bash` 的 `dshHome` 配置迁往那里，因此挂载 shell 工具的组合也必须挂载 `bash-env`（spine bundle 已如此）。
 - Windows 专属语义（CRLF 归一化、强制终止 exit-1/signal-null、仅 POSIX 的自信号）一如既往由测试钉住。
 - pwsh 工具的 per-file 覆盖门禁由可脚本化的 fake-executor 套件（`tests/tools.spec.ts`）承担；真实 pwsh 的集成与 Loader 组合套件在无 `pwsh` 的宿主自跳过，与 bash 套件的分工一致。