fix(copilot): use gpt-4.1 as default model and 127.0.0.1 for local connections

Key changes:
- Changed default model from claude-sonnet-4.5 to gpt-4.1 (free tier compatible)
- Updated all Claude models to minPlan: 'pro' (requires paid Copilot subscription)
- Replaced 'localhost' with '127.0.0.1' for more reliable local connections
  (bypasses DNS resolution and potential IPv6 issues)
- Updated UI presets: replaced Claude Haiku with Raptor Mini in free tier
- Fixed FREE_PRESETS to only include actually free models

This fixes the "model_not_supported" error when using free tier GitHub Copilot
subscription, which doesn't have access to Claude models.

ui/src/components/copilot/copilot-config-form.tsx

@@ -39,6 +39,7 @@ const CodeEditor = lazy(() =>
 
 // Model presets for quick configuration
 // Grouped by tier: Free (available to all) and Paid (requires Pro+)
+// Note: ALL Claude models require paid Copilot subscription
 const FREE_PRESETS = [
   {
     name: 'GPT-4.1 (Free)',
@@ -57,12 +58,12 @@ const FREE_PRESETS = [
     haiku: 'gpt-5-mini',
   },
   {
-    name: 'Claude Haiku 4.5 (Free)',
-    description: 'Free tier - fast Anthropic model',
-    default: 'claude-haiku-4.5',
-    opus: 'claude-haiku-4.5',
-    sonnet: 'claude-haiku-4.5',
-    haiku: 'claude-haiku-4.5',
+    name: 'Raptor Mini (Free)',
+    description: 'Free tier - fine-tuned for coding',
+    default: 'raptor-mini',
+    opus: 'raptor-mini',
+    sonnet: 'raptor-mini',
+    haiku: 'raptor-mini',
   },
 ];