fix: support windows insaits python shims

scripts/hooks/insaits-security-wrapper.js

@@ -15,6 +15,7 @@ const path = require('path');
 const { spawnSync } = require('child_process');
 
 const MAX_STDIN = 1024 * 1024;
+const WINDOWS_SHELL_UNSAFE_PATH_CHARS = /[&|<>^%!]/;
 
 function isEnabled(value) {
   return ['1', 'true', 'yes', 'on'].includes(String(value || '').toLowerCase());
@@ -37,17 +38,33 @@ process.stdin.on('end', () => {
   const scriptDir = __dirname;
   const pyScript = path.join(scriptDir, 'insaits-security-monitor.py');
 
-  // Try python3 first (macOS/Linux), fall back to python (Windows)
-  const pythonCandidates = ['python3', 'python'];
+  // Prefer real Windows executables before .cmd shims so shell execution is
+  // only used for wrapper scripts such as pyenv/npm-style shims.
+  const pythonCandidates = process.platform === 'win32'
+    ? ['python3.exe', 'python.exe', 'python3.cmd', 'python.cmd', 'python3', 'python']
+    : ['python3', 'python'];
   let result;
 
   for (const pythonBin of pythonCandidates) {
+    const useWindowsShell = process.platform === 'win32' && /\.(cmd|bat)$/i.test(pythonBin);
+    if (useWindowsShell && (
+      WINDOWS_SHELL_UNSAFE_PATH_CHARS.test(pythonBin)
+      || WINDOWS_SHELL_UNSAFE_PATH_CHARS.test(pyScript)
+    )) {
+      result = {
+        error: new Error(`Unsafe Windows Python shim path: ${pythonBin}`),
+      };
+      break;
+    }
+
     result = spawnSync(pythonBin, [pyScript], {
       input: raw,
       encoding: 'utf8',
       env: process.env,
       cwd: process.cwd(),
       timeout: 14000,
+      shell: useWindowsShell,
+      windowsHide: true,
     });
 
     // ENOENT means binary not found - try next candidate

tests/hooks/insaits-security-wrapper.test.js

@@ -21,8 +21,40 @@ function cleanup(dirPath) {
 }
 
 function writeFakePython(binDir) {
-  const fakePython = path.join(binDir, 'python3');
   fs.mkdirSync(binDir, { recursive: true });
+  if (process.platform === 'win32') {
+    const fakePythonJs = path.join(binDir, 'fake-python.js');
+    const fakePythonCmd = path.join(binDir, 'python3.cmd');
+    fs.writeFileSync(fakePythonJs, [
+      "'use strict';",
+      "const fs = require('fs');",
+      "const mode = process.env.FAKE_INSAITS_MODE || 'clean';",
+      "if (mode === 'clean') {",
+      "  fs.readFileSync(0, 'utf8');",
+      "  process.exit(0);",
+      "}",
+      "if (mode === 'echo') {",
+      "  process.stdout.write(fs.readFileSync(0, 'utf8'));",
+      "  process.exit(0);",
+      "}",
+      "if (mode === 'block') {",
+      "  process.stdout.write('blocked by monitor\\n');",
+      "  process.stderr.write('monitor warning\\n');",
+      "  process.exit(2);",
+      "}",
+      "if (mode === 'error') {",
+      "  process.stderr.write('spawned but failed\\n');",
+      "  process.exit(1);",
+      "}",
+    ].join('\n'), 'utf8');
+    fs.writeFileSync(fakePythonCmd, [
+      '@echo off',
+      `"${process.execPath}" "%~dp0fake-python.js" %*`,
+    ].join('\r\n'), 'utf8');
+    return;
+  }
+
+  const fakePython = path.join(binDir, 'python3');
   fs.writeFileSync(fakePython, [
     '#!/bin/sh',
     'mode="${FAKE_INSAITS_MODE:-clean}"',