Anthropic Agents (.NET) sample uses APIKey, but the actual property is ApiKey

[Mrknief]

The C# sample under "Basic Agent Creation (Anthropic Public API)" on this page shows:

AnthropicClient client = new() { APIKey = apiKey };

This doesn't compile — Microsoft.Agents.AI.Anthropic 1.13.0-preview.260703.1 (which depends on the official Anthropic SDK 12.20.0) exposes the property as ApiKey, not APIKey (confirmed against the official C# SDK docs, which consistently use ApiKey). Hit CS0117: 'AnthropicClient' does not contain a definition for 'APIKey' following this sample verbatim.

All three code blocks on the page using this pattern (public API, Foundry API key, Foundry Azure credentials) have the same typo.