Update Learning Hub: composer model menu, CIMD OAuth, model picker cleanup

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

website/src/content/docs/learning-hub/copilot-configuration-basics.md

@@ -3,7 +3,7 @@ title: 'Copilot Configuration Basics'
 description: 'Learn how to configure GitHub Copilot at user, workspace, and repository levels to optimize your AI-assisted development experience.'
 authors:
   - GitHub Copilot Learning Hub Team
-lastUpdated: 2026-09-01
+lastUpdated: 2026-09-03
 estimatedReadingTime: '10 minutes'
 tags:
   - configuration
@@ -459,6 +459,8 @@ The model picker opens in a **full-screen view** with inline reasoning effort ad
 
 **Model family aliases** (v1.0.64+): Instead of typing a full model name, you can use short family aliases in the model setting: `opus`, `sonnet`, `haiku` (Anthropic), and `gpt`, `gemini` (Google/OpenAI). The CLI resolves the alias to the latest available model in that family. This is especially useful in scripts or configuration files where you want to track the best model in a family without hardcoding a version string. Recent models available include **Claude Opus 5** (v1.0.75+), the latest in Anthropic's Opus family for the most demanding tasks, **Grok 4.5** (v1.0.76+) from xAI, and **Gemini 3.7 Flash** (v1.0.81+). **Grok 4.6** (v1.0.81+) also gains support for the `xhigh` reasoning effort level, one step above `high`, for the most demanding reasoning tasks.
 
+> **Model picker cleanup (v1.0.83+)**: Retired Claude and Gemini models are no longer shown in `/model` picker results, keeping the list focused on models that are still supported.
+
 **Plan mode model** *(v1.0.74+)*: When using plan mode (which blocks file mutations and keeps changes in a planning phase), you can assign a *separate* model specifically for planning — different from your regular session model. This lets you use a fast, cost-effective model for plan drafting while keeping a more capable model on standby for the implementation phase:
 
 ```