chore: add API key setup question to Exolab AI plugin configuration

## CHANGES

- Add "openaiapi" to VSCode spell check dictionary
- Include API key setup question in Exolab client
- Configure API key as required field for setup
- Maintain existing API base URL configuration order

Author: ksylvan

.vscode/settings.json

@@ -80,6 +80,7 @@
 		"nometa",
 		"numpy",
 		"ollama",
+		"openaiapi",
 		"opencode",
 		"openrouter",
 		"otiai",

internal/plugins/ai/exolab/exolab.go

@@ -13,6 +13,7 @@ func NewClient() (ret *Client) {
 	ret = &Client{}
 	ret.Client = openai.NewClientCompatibleNoSetupQuestions("Exolab", ret.configure)
 
+	ret.ApiKey = ret.AddSetupQuestion("API Key", false)
 	ret.ApiBaseURL = ret.AddSetupQuestion("API Base URL", true)
 	ret.ApiBaseURL.Value = "http://localhost:52415"