fix(cli): preserve selected auth type on startup auth failure

[zy6p]

TLDR

Stop clearing security.auth.selectedType when startup auto-auth fails.

This preserves user auth configuration (for example OpenAI-compatible + custom envKey) and avoids rewriting settings.json into a confusing state when an env var is temporarily missing.

Dive Deeper

Root cause:

• initializeApp() called settings.setValue(..., 'security.auth.selectedType', undefined) whenever performInitialAuth() returned an error.
• For setups like envKey: OLLAMA_API_KEY, forgetting to export the env var made startup auth fail and wiped selectedType from user settings.

What changed:

• Removed the destructive fallback write in packages/cli/src/core/initializer.ts.
• Kept the existing UX behavior: auth error still opens auth dialog (shouldOpenAuthDialog remains true).
• Added regression tests in packages/cli/src/core/initializer.test.ts.

Reviewer Test Plan

1. Configure settings.json with:
   • security.auth.selectedType = "openai"
   • an OpenAI-compatible model that uses a custom envKey (e.g. OLLAMA_API_KEY)
2. Ensure that env key is missing in shell (unset OLLAMA_API_KEY).
3. Start qwen.
4. Verify:
   • auth error is shown and auth dialog opens
   • settings.json still keeps security.auth.selectedType unchanged

Testing Matrix

	🍏	🪟	🐧
npm run	❓	❓	✅
npx	❓	❓	❓
Docker	❓	❓	❓
Podman	❓	-	-
Seatbelt	❓	-	-

Linked issues / bugs

Fixes #2049