start/setup/update.sh: refuse to run on a Windows-hosted shell

A Windows user running the bash helper scripts (WSL, or Git Bash /
MSYS2 / MinGW / Cygwin) used to fail deep in the venv/PC-SC logic - under
WSL the Linux guest cannot reach the Windows PC/SC readers, and a
mingw/msys shell has the wrong (bin/) venv layout.  Each helper now
detects Windows (WSL via /proc/version, mingw/msys/cygwin via uname -s)
up front and exits 2 with a pointer at the matching .bat script.  Users
who deliberately want the WSL/Cygwin flow can run the underlying commands
directly, without the helpers.

Bumps VERSION to 3.40.4 and the SW cache to simple-v490.

tests/test_pcsc_startup.py

@@ -165,6 +165,18 @@ class SourcePins(unittest.TestCase):
         self.assertIn('%HTTP_HOST%:%HTTP_PORT%', src)
         self.assertNotIn('http://127.0.0.1:8080', src)
 
+    def test_the_start_script_guards_windows_and_points_to_start_bat(self):
+        src = (Path(m.__file__).parent.parent / 'start.sh').read_text()
+        self.assertIn('microsoft /proc/version', src)
+        self.assertIn('MINGW|MSYS|CYGWIN', src)
+        self.assertIn('Use start.bat from a Windows command prompt', src)
+
+    def test_the_update_script_guards_windows_and_points_to_update_bat(self):
+        src = (Path(m.__file__).parent.parent / 'update.sh').read_text()
+        self.assertIn('microsoft /proc/version', src)
+        self.assertIn('MINGW|MSYS|CYGWIN', src)
+        self.assertIn('Use update.bat from a Windows command prompt', src)
+
 
 if __name__ == '__main__':
     unittest.main()