feat(windows): prefer pwsh over powershell.exe for Shell tool

Environment.detect() resolves pwsh via PATH, then default install under Program Files\PowerShell\7, then inbox System32 powershell.exe, then PATH powershell. shell_name remains Windows PowerShell so Shell and background workers keep using -command.

Add tests for pwsh-from-PATH and pwsh-from-install-dir; mock shutil.which in Windows environment tests. Document in CHANGELOG (en/zh).

Author: scwf

CHANGELOG.md

@@ -19,6 +19,7 @@ Only write entries that are worth mentioning to users.
 - Shell: Exclude empty current session from `/sessions` picker — completely empty sessions (no conversation history and no custom title) are no longer shown in the session list; sessions with a custom title are still displayed
 - Shell: Fix slash command completion Enter key behavior — accepting a completion now submits in a single Enter press; auto-submit is limited to slash command completions only; file mention completions (`@`) accept without submitting so the user can continue editing; re-completion after accepting is suppressed to prevent stale completion state
 - Shell: Add directory scope toggle to `/sessions` picker — press `Ctrl+A` to switch between showing sessions for the current working directory only or across all known directories; uses a new full-screen session picker UI with header scope indicator and footer hint bar
+- Tool: On Windows, the Shell tool now prefers PowerShell 7+ (`pwsh`) when available, and falls back to inbox Windows PowerShell (`powershell.exe`)
 - Shell: Add `/btw` side question command — ask a quick question during streaming without interrupting the main conversation; uses the same system prompt and tool definitions for prompt cache alignment; responses display in a scrollable modal panel with streaming support
 - Shell: Redesign bottom dynamic area — split the monolithic `visualize.py` (1865 lines) into a modular package (`visualize/`) with dedicated modules for input routing, interactive prompts, approval/question panels, and btw modal; unify input semantics with `classify_input()` for consistent command routing
 - Shell: Add queue and steer dual-channel input during streaming — Enter queues messages for delivery after the current turn; Ctrl+S injects messages immediately into the running turn's context; queued messages display in the prompt area with count indicator and can be recalled with ↑

docs/en/release-notes/changelog.md

@@ -12,6 +12,7 @@ This page documents the changes in each Kimi Code CLI release.
 - Shell: Exclude empty current session from `/sessions` picker — completely empty sessions (no conversation history and no custom title) are no longer shown in the session list; sessions with a custom title are still displayed
 - Shell: Fix slash command completion Enter key behavior — accepting a completion now submits in a single Enter press; auto-submit is limited to slash command completions only; file mention completions (`@`) accept without submitting so the user can continue editing; re-completion after accepting is suppressed to prevent stale completion state
 - Shell: Add directory scope toggle to `/sessions` picker — press `Ctrl+A` to switch between showing sessions for the current working directory only or across all known directories; uses a new full-screen session picker UI with header scope indicator and footer hint bar
+- Tool: On Windows, the Shell tool now prefers PowerShell 7+ (`pwsh`) when available, and falls back to inbox Windows PowerShell (`powershell.exe`)
 - Shell: Add `/btw` side question command — ask a quick question during streaming without interrupting the main conversation; uses the same system prompt and tool definitions for prompt cache alignment; responses display in a scrollable modal panel with streaming support
 - Shell: Redesign bottom dynamic area — split the monolithic `visualize.py` (1865 lines) into a modular package (`visualize/`) with dedicated modules for input routing, interactive prompts, approval/question panels, and btw modal; unify input semantics with `classify_input()` for consistent command routing
 - Shell: Add queue and steer dual-channel input during streaming — Enter queues messages for delivery after the current turn; Ctrl+S injects messages immediately into the running turn's context; queued messages display in the prompt area with count indicator and can be recalled with ↑

docs/zh/release-notes/changelog.md

@@ -12,6 +12,7 @@
 - Shell：从 `/sessions` 选择器中排除空的当前会话——完全为空的会话（既无对话记录也无自定义标题）不再显示在会话列表中；有自定义标题的会话仍然正常显示
 - Shell：修复斜杠命令补全 Enter 键行为——接受补全后现在通过一次 Enter 即可提交命令；自动提交仅限于斜杠命令补全，文件引用（`@`）补全接受后不提交以便继续编辑；接受补全时抑制重新补全，防止过时的补全状态
 - Shell：为 `/sessions` 会话选择器新增目录范围切换功能——按 `Ctrl+A` 可在"仅当前工作目录"和"所有已知目录"之间切换会话列表；采用全屏会话选择器 UI，顶部显示当前范围，底部显示快捷键提示
+- Tool：Windows 上 Shell 工具在可用时优先使用 PowerShell 7+（`pwsh`），否则回退至系统自带的 Windows PowerShell（`powershell.exe`）
 - Shell：新增 `/btw` 侧问命令——在 streaming 期间提出快速问题，不打断主对话；使用相同的系统提示词和工具定义以对齐 Prompt 缓存；响应在可滚动的模态面板中显示，支持流式输出
 - Shell：重新设计底部动态区——将单体 `visualize.py`（1865 行）拆分为模块化包（`visualize/`），包含输入路由、交互式提示、审批/提问面板和 btw 模态面板等独立模块；通过 `classify_input()` 统一输入语义，实现一致的命令路由
 - Shell：新增 streaming 期间的排队和 steer 双通道输入——Enter 将消息排队，在当前轮次结束后发送；Ctrl+S 将消息立即注入到正在运行的轮次上下文中；排队消息在提示区域显示计数指示器，可通过 ↑ 键召回编辑

src/kimi_cli/utils/environment.py

@@ -2,12 +2,53 @@
 
 import os
 import platform
+import shutil
 from dataclasses import dataclass
 from typing import Literal
 
 from kaos.path import KaosPath
 
 
+def _windows_shell_candidates() -> list[KaosPath]:
+    """PowerShell executables to probe, in order.
+
+    Prefer PowerShell 7+ (`pwsh`) when present, then fall back to Windows PowerShell 5.1
+    (`powershell.exe`), matching common developer installs while remaining usable on systems
+    that only ship the inbox shell.
+    """
+    candidates: list[KaosPath] = []
+    seen: set[str] = set()
+
+    def add(path: str) -> None:
+        normalized = os.path.normcase(os.path.normpath(path))
+        if normalized not in seen:
+            seen.add(normalized)
+            candidates.append(KaosPath(path))
+
+    pwsh = shutil.which("pwsh")
+    if pwsh:
+        add(pwsh)
+
+    program_files = os.environ.get("ProgramW6432") or os.environ.get(
+        "ProgramFiles", r"C:\Program Files"
+    )
+    add(os.path.join(program_files, "PowerShell", "7", "pwsh.exe"))
+
+    system_root = os.environ.get("SYSTEMROOT", r"C:\Windows")
+    add(
+        os.path.join(
+            system_root, "System32", "WindowsPowerShell", "v1.0", "powershell.exe"
+        )
+    )
+
+    powershell = shutil.which("powershell")
+    if powershell:
+        add(powershell)
+
+    add("powershell.exe")
+    return candidates
+
+
 @dataclass(slots=True, frozen=True, kw_only=True)
 class Environment:
     os_kind: Literal["Windows", "Linux", "macOS"] | str
@@ -33,16 +74,8 @@ async def detect() -> Environment:
 
         if os_kind == "Windows":
             shell_name = "Windows PowerShell"
-            system_root = os.environ.get("SYSTEMROOT", r"C:\Windows")
-            possible_paths = [
-                KaosPath(
-                    os.path.join(
-                        system_root, "System32", "WindowsPowerShell", "v1.0", "powershell.exe"
-                    )
-                ),
-            ]
             fallback_path = KaosPath("powershell.exe")
-            for path in possible_paths:
+            for path in _windows_shell_candidates():
                 if await path.is_file():
                     shell_path = path
                     break

tests/utils/test_utils_environment.py

@@ -32,13 +32,15 @@ async def test_environment_detection_windows(monkeypatch):
     monkeypatch.setattr(platform, "machine", lambda: "AMD64")
     monkeypatch.setattr(platform, "version", lambda: "10.0.19044")
     monkeypatch.setenv("SYSTEMROOT", r"C:\Windows")
+    monkeypatch.delenv("ProgramW6432", raising=False)
+    monkeypatch.setattr("kimi_cli.utils.environment.shutil.which", lambda *_a, **_k: None)
 
     expected = os.path.join(
         r"C:\Windows", "System32", "WindowsPowerShell", "v1.0", "powershell.exe"
     )
 
     async def _mock_is_file(self: KaosPath) -> bool:
-        return str(self) == expected
+        return os.path.normcase(str(self)) == os.path.normcase(expected)
 
     monkeypatch.setattr(KaosPath, "is_file", _mock_is_file)
 
@@ -49,7 +51,58 @@ async def _mock_is_file(self: KaosPath) -> bool:
     assert env.os_arch == "AMD64"
     assert env.os_version == "10.0.19044"
     assert env.shell_name == "Windows PowerShell"
-    assert str(env.shell_path) == expected
+    assert os.path.normcase(str(env.shell_path)) == os.path.normcase(expected)
+
+
+@pytest.mark.skipif(platform.system() == "Windows", reason="Skipping test on Windows")
+async def test_environment_detection_windows_prefers_pwsh_from_path(monkeypatch):
+    monkeypatch.setattr(platform, "system", lambda: "Windows")
+    monkeypatch.setattr(platform, "machine", lambda: "AMD64")
+    monkeypatch.setattr(platform, "version", lambda: "10.0.19044")
+    monkeypatch.setenv("SYSTEMROOT", r"C:\Windows")
+    expected = os.path.join(r"C:\Program Files", "PowerShell", "7", "pwsh.exe")
+
+    def _which(cmd: str, path: str | None = None) -> str | None:
+        if cmd == "pwsh":
+            return expected
+        return None
+
+    monkeypatch.setattr("kimi_cli.utils.environment.shutil.which", _which)
+
+    async def _mock_is_file(self: KaosPath) -> bool:
+        return os.path.normcase(str(self)) == os.path.normcase(expected)
+
+    monkeypatch.setattr(KaosPath, "is_file", _mock_is_file)
+
+    from kimi_cli.utils.environment import Environment
+
+    env = await Environment.detect()
+    assert env.shell_name == "Windows PowerShell"
+    assert os.path.normcase(str(env.shell_path)) == os.path.normcase(expected)
+
+
+@pytest.mark.skipif(platform.system() == "Windows", reason="Skipping test on Windows")
+async def test_environment_detection_windows_prefers_pwsh_from_program_files(monkeypatch):
+    monkeypatch.setattr(platform, "system", lambda: "Windows")
+    monkeypatch.setattr(platform, "machine", lambda: "AMD64")
+    monkeypatch.setattr(platform, "version", lambda: "10.0.19044")
+    monkeypatch.setenv("SYSTEMROOT", r"C:\Windows")
+    monkeypatch.delenv("ProgramW6432", raising=False)
+    monkeypatch.setenv("ProgramFiles", r"C:\Program Files")
+    monkeypatch.setattr("kimi_cli.utils.environment.shutil.which", lambda *_a, **_k: None)
+
+    expected = os.path.join(r"C:\Program Files", "PowerShell", "7", "pwsh.exe")
+
+    async def _mock_is_file(self: KaosPath) -> bool:
+        return os.path.normcase(str(self)) == os.path.normcase(expected)
+
+    monkeypatch.setattr(KaosPath, "is_file", _mock_is_file)
+
+    from kimi_cli.utils.environment import Environment
+
+    env = await Environment.detect()
+    assert env.shell_name == "Windows PowerShell"
+    assert os.path.normcase(str(env.shell_path)) == os.path.normcase(expected)
 
 
 @pytest.mark.skipif(platform.system() == "Windows", reason="Skipping test on Windows")
@@ -58,6 +111,7 @@ async def test_environment_detection_windows_fallback(monkeypatch):
     monkeypatch.setattr(platform, "machine", lambda: "AMD64")
     monkeypatch.setattr(platform, "version", lambda: "10.0.19044")
     monkeypatch.setenv("SYSTEMROOT", r"C:\Windows")
+    monkeypatch.setattr("kimi_cli.utils.environment.shutil.which", lambda *_a, **_k: None)
 
     async def _mock_is_file(self: KaosPath) -> bool:
         return False