fix: Windows/WSL compatibility for shell tools and CLI helpers

- exec_tool: add Windows shell detection (pwsh/cmd), use taskkill for process kill
- shell_detect: skip Unix paths on Windows, add pwsh/cmd fallback chain
- dev.py: replace all `which` subprocess calls with shutil.which()
- test_hanzo_dev: use shutil.which() instead of subprocess which

pkg/hanzo-async/uv.lock

@@ -22,7 +22,7 @@ wheels = [
 
 [[package]]
 name = "hanzo-async"
-version = "0.1.0"
+version = "0.1.2"
 source = { editable = "." }
 dependencies = [
     { name = "aiofiles" },

pkg/hanzo-mcp/uv.lock

@@ -1290,7 +1290,7 @@ wheels = [
 
 [[package]]
 name = "hanzo-mcp"
-version = "0.12.6"
+version = "0.12.7"
 source = { editable = "." }
 dependencies = [
     { name = "fastmcp" },
@@ -1323,7 +1323,6 @@ dependencies = [
     { name = "pydantic" },
     { name = "pydantic-settings" },
     { name = "typing-extensions" },
-    { name = "uvloop", marker = "sys_platform != 'win32'" },
 ]
 
 [package.optional-dependencies]
@@ -1363,6 +1362,7 @@ memory = [
 performance = [
     { name = "orjson" },
     { name = "ujson" },
+    { name = "uvloop", marker = "sys_platform != 'win32'" },
 ]
 publish = [
     { name = "build" },
@@ -1441,7 +1441,7 @@ requires-dist = [
     { name = "types-setuptools", marker = "extra == 'dev'", specifier = ">=69.5.0" },
     { name = "typing-extensions", specifier = ">=4.13.0" },
     { name = "ujson", marker = "extra == 'performance'", specifier = ">=5.7.0" },
-    { name = "uvloop", marker = "sys_platform != 'win32'", specifier = ">=0.22.1" },
+    { name = "uvloop", marker = "sys_platform != 'win32' and extra == 'performance'", specifier = ">=0.22.1" },
     { name = "websockets", marker = "extra == 'ide'", specifier = ">=12.0" },
 ]
 provides-extras = ["memory", "repl", "ide", "interactive", "dev", "docs", "test", "performance", "publish"]

pkg/hanzo-tools-shell/hanzo_tools/shell/exec_tool.py

@@ -58,13 +58,22 @@ class ExecTool(BaseTool):
         self._register_proc_actions()
 
     def _resolve_shell(self) -> str:
-        """Resolve shell - prefer zsh, fallback to bash/sh."""
+        """Resolve shell - prefer zsh, fallback to bash/sh. On Windows: pwsh/cmd."""
+        import sys
         import shutil
 
         force_shell = os.environ.get("HANZO_MCP_FORCE_SHELL")
         if force_shell:
             return force_shell
 
+        # On Windows, prefer PowerShell/cmd
+        if sys.platform == "win32":
+            for shell in ("pwsh", "powershell", "cmd"):
+                found = shutil.which(shell)
+                if found:
+                    return found
+            return "cmd.exe"
+
         for shell in ["zsh", "bash", "fish", "dash", "sh"]:
             for prefix in ["/opt/homebrew/bin", "/usr/local/bin", "/bin", "/usr/bin"]:
                 full_path = f"{prefix}/{shell}"
@@ -372,6 +381,8 @@ Auto-backgrounds commands after {AUTO_BACKGROUND_TIMEOUT}s.
                 )
 
             # Resolve signal
+            import sys as _sys
+
             if isinstance(signal, str):
                 signal_map = {
                     "TERM": 15,
@@ -385,7 +396,17 @@ Auto-backgrounds commands after {AUTO_BACKGROUND_TIMEOUT}s.
                 sig_num = signal
 
             try:
-                os.kill(pid, sig_num)
+                if _sys.platform == "win32":
+                    # On Windows, os.kill() only supports SIGTERM (terminate)
+                    # and signal 0 (existence check). Use terminate semantics.
+                    import subprocess
+                    subprocess.call(
+                        ["taskkill", "/F", "/PID", str(pid)],
+                        stdout=subprocess.DEVNULL,
+                        stderr=subprocess.DEVNULL,
+                    )
+                else:
+                    os.kill(pid, sig_num)
                 return {
                     "proc_id": proc_id,
                     "pid": pid,

pkg/hanzo-tools-shell/hanzo_tools/shell/shell_detect.py

@@ -280,6 +280,10 @@ def resolve_shell_path(shell_name: str) -> Optional[str]:
         if os.path.isfile(force_shell) and os.access(force_shell, os.X_OK):
             return force_shell
 
+    # On Windows, skip Unix-specific paths and use shutil.which directly
+    if os.name == "nt":
+        return shutil.which(shell_name)
+
     # Priority paths - Homebrew first on macOS
     search_paths = [
         f"/opt/homebrew/bin/{shell_name}",  # Apple Silicon Homebrew
@@ -337,7 +341,14 @@ def get_active_shell() -> Tuple[str, str]:
         best_path = resolve_shell_path(chosen_name)
         return chosen_name, best_path or chosen_path
 
-    # Fallback: if detected shell isn't supported, default to zsh
+    # Fallback: if detected shell isn't supported, default to zsh (or pwsh on Windows)
+    if os.name == "nt":
+        for fallback in ["pwsh", "powershell", "cmd"]:
+            path = shutil.which(fallback)
+            if path:
+                return fallback, path
+        return "cmd", "cmd.exe"
+
     for fallback in ["zsh", "bash", "fish", "dash"]:
         path = resolve_shell_path(fallback)
         if path:

pkg/hanzo-tools-shell/uv.lock

@@ -439,7 +439,7 @@ wheels = [
 
 [[package]]
 name = "hanzo-tools-shell"
-version = "0.6.1"
+version = "0.6.2"
 source = { editable = "." }
 dependencies = [
     { name = "hanzo-async" },

pkg/hanzo/src/hanzo/dev.py

@@ -12,6 +12,7 @@ import os
 import sys
 import json
 import time
+import shutil
 import signal
 import asyncio
 import logging
@@ -244,6 +245,8 @@ class HanzoDevOrchestrator:
 
     def _find_claude_code(self) -> str:
         """Find Claude Code executable."""
+        import shutil
+
         # Check common locations
         possible_paths = [
             "/usr/local/bin/claude",
@@ -255,7 +258,7 @@ class HanzoDevOrchestrator:
         for path in possible_paths:
             expanded = Path(path).expanduser()
             if expanded.exists() or (
-                path == "claude" and os.system(f"which {path} >/dev/null 2>&1") == 0
+                path == "claude" and shutil.which(path) is not None
             ):
                 return str(expanded) if expanded.exists() else path
 
@@ -1472,13 +1475,13 @@ Examples:
         """Use OpenAI CLI (Codex) - the official OpenAI CLI tool."""
         try:
             import json
+            import shutil
             import subprocess
 
             console.print("[dim]Using OpenAI CLI (Codex)...[/dim]")
 
             # Check if openai CLI is installed
-            result = subprocess.run(["which", "openai"], capture_output=True, text=True)
-            if result.returncode != 0:
+            if not shutil.which("openai"):
                 console.print("[red]OpenAI CLI not installed![/red]")
                 console.print("[yellow]To install:[/yellow]")
                 console.print("  • pip install openai-cli")
@@ -1517,6 +1520,7 @@ Examples:
         """Use Claude Desktop/Code CLI."""
         try:
             import os
+            import shutil
             import subprocess
 
             console.print("[dim]Using Claude Desktop...[/dim]")
@@ -1531,11 +1535,7 @@ Examples:
 
             claude_path = None
             for path in claude_paths:
-                if (
-                    os.path.exists(path)
-                    or subprocess.run(["which", path], capture_output=True).returncode
-                    == 0
-                ):
+                if os.path.exists(path) or shutil.which(path) is not None:
                     claude_path = path
                     break
 
@@ -1587,13 +1587,13 @@ Examples:
     async def _use_gemini_cli(self, message: str):
         """Use Gemini CLI."""
         try:
+            import shutil
             import subprocess
 
             console.print("[dim]Using Gemini CLI...[/dim]")
 
             # Check if gemini CLI is installed
-            result = subprocess.run(["which", "gemini"], capture_output=True, text=True)
-            if result.returncode != 0:
+            if not shutil.which("gemini"):
                 console.print("[red]Gemini CLI not installed![/red]")
                 console.print("[yellow]To install:[/yellow]")
                 console.print("  • pip install google-generativeai-cli")

tests/test_hanzo_dev.py

@@ -7,6 +7,7 @@ Tests all orchestrator modes and ensures everything works.
 import os
 import sys
 import time
+import shutil
 import asyncio
 import subprocess
 from pathlib import Path
@@ -24,11 +25,7 @@ def print_test(name):
 
 def check_command_exists(cmd):
     """Check if a command exists."""
-    try:
-        result = subprocess.run(["which", cmd], capture_output=True, text=True)
-        return result.returncode == 0
-    except Exception:
-        return False
+    return shutil.which(cmd) is not None
 
 
 async def test_imports():