fix(setup): preserve overridden runner variables and test isolation on Windows

Support case-insensitive environment value lookup in ClientRegistrationIdentity while preserving JavaScript property order precedence with findLast(). Add unit regression coverage for ambient uppercase npm variables on Windows. Isolate USERPROFILE in cliSetup tests so child processes do not touch the host profile directory. Harden JSON decision extraction in runJourney against ConPTY trailing ANSI escape codes. Deterministically sequence multiselect prompt navigation before confirmation. Filter ambient runner variables case-insensitively before launching interactive setup completion tests.

src/application/ClientRegistrationIdentity.ts

@@ -13,8 +13,9 @@ const environmentValue = (
   platform: NodeJS.Platform,
 ): string | undefined => {
   if (platform !== "win32") return environment[name];
-  const key = Object.keys(environment).find(
-    (candidate) => candidate.toLowerCase() === name,
+  const target = name.toLowerCase();
+  const key = Object.keys(environment).findLast(
+    (candidate) => candidate.toLowerCase() === target,
   );
   return key === undefined ? undefined : environment[key];
 };