feat: Azure credential chain logging (#2413)

Co-authored-by: Michael Paquette <mpaquette@pax8.com>
Co-authored-by: Alice Hau <ahau@squareup.com>

ui/desktop/src/components/settings/models/hardcoded_stuff.tsx

@@ -64,7 +64,6 @@ export const required_keys = {
   Google: ['GOOGLE_API_KEY'],
   OpenRouter: ['OPENROUTER_API_KEY'],
   'Azure OpenAI': [
-    'AZURE_OPENAI_API_KEY',
     'AZURE_OPENAI_ENDPOINT',
     'AZURE_OPENAI_DEPLOYMENT_NAME',
     'AZURE_OPENAI_API_VERSION',

ui/desktop/src/components/settings_v2/providers/ProviderRegistry.tsx

@@ -173,11 +173,12 @@ export const PROVIDER_REGISTRY: ProviderRegistry[] = [
     details: {
       id: 'azure_openai',
       name: 'Azure OpenAI',
-      description: 'Access Azure OpenAI models',
+      description: 'Access Azure OpenAI models using API key or Azure credentials. If no API key is provided, Azure credential chain will be used.',
       parameters: [
         {
           name: 'AZURE_OPENAI_API_KEY',
           is_secret: true,
+          required: false,
         },
         {
           name: 'AZURE_OPENAI_ENDPOINT',