Intercept the WSL OpenBao browser launch.

OpenBao opens the login with cmd.exe /c start, so the xdg-open launcher
never ran. The attended PATH now supplies cmd.exe for that one allowlisted
URL and opens it in the empty Playwright Chromium profile.

Assistant: grok
Assistant-Session: 01a198fa-fd27-7e41-a0a2-57355c3e4efd

tests/test_operator_browser.py

@@ -40,3 +40,9 @@ class BrowserBoundary(unittest.TestCase):
             binary.chmod(0o755)
             self.assertEqual(launcher['chromium_executable'](spec, root), str(binary))
             self.assertEqual(launcher['chromium_executable'](root/'missing.json', root), '')
+    def test_wsl_cmd_start_is_the_login_opener(self):
+        url='https://kc.coulomb.social/authorize?'+urlencode({'redirect_uri':'http://127.0.0.1:8250/oidc/callback','state':'test'})
+        escaped=url.replace('&','^&')
+        self.assertEqual(launcher['classify_cmd'](['/c','start',escaped]), ('open', url))
+        self.assertEqual(launcher['classify_cmd'](['/c','start','https://evil.example/']), ('reject', ''))
+        self.assertEqual(launcher['classify_cmd'](['/c','dir']), ('delegate', ''))