Fix quantized sizes not showing in collapsed family headers

When "Show quantized models" is enabled, collapsed family headers were only showing base sizes (e.g., "27B") instead of including quantized variants (e.g., "27B-Q4").

The bug was in CatalogSection.buildCatalogItems() where size collection used model.size instead of model.sizeLabel. Since model.size returns just the base size for all models, quantized variants weren't distinguished in the header. Now uses model.sizeLabel which includes the quantization suffix for quantized models.

Author: erusev

LlamaBarn/Menu/Sections.swift

@@ -281,8 +281,8 @@ final class CatalogSection {
     // Group models by family to collect unique sizes
     var familySizes: [String: [String]] = [:]
     for model in sortedModels {
-      if !familySizes[model.family, default: []].contains(model.size) {
-        familySizes[model.family, default: []].append(model.size)
+      if !familySizes[model.family, default: []].contains(model.sizeLabel) {
+        familySizes[model.family, default: []].append(model.sizeLabel)
       }
     }