fix(catalog): extractLayoutRef reads page-template LayoutCall (completes layout coverage)

Page templates (Forms$PageTemplate, e.g. all 46 Atlas_Web_Content templates) nest
their layout under LayoutCall, whereas regular pages (Forms$Form) use FormCall.
extractLayoutRef only read FormCall, so every page template reported no layout —
on MxGraphStudioDemo only 22 of 68 pages had a LayoutRef, and the refs table had
22 layout edges.

Both calls nest the same Form (string QN) / Layout (binary GUID) fields, so fall
back to LayoutCall when FormCall is absent. Now 68/68 pages resolve a layout
(e.g. Phone_Detail -> Atlas_Core.Phone_Default) and refs layout edges go 22 -> 68.
TestExtractLayoutRef gains a LayoutCall (page-template) case.

This closes the "layout extraction is partial" follow-up noted on #663 gap 3.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Author: ako

mdl/catalog/builder_pages.go

@@ -187,20 +187,28 @@ type rawWidgetInfo struct {
 	AttributeRef string
 }
 
-// extractLayoutRef extracts the layout reference from raw page BSON.
+// extractLayoutRef extracts the layout reference from raw page BSON. Regular
+// pages (Forms$Form) carry the layout under FormCall; page templates
+// (Forms$PageTemplate) carry it under LayoutCall instead. Both nest the same
+// Form (string qualified name) / Layout (binary GUID) fields, so try FormCall
+// first and fall back to LayoutCall — without the fallback every page template
+// reports no layout (e.g. all 46 Atlas_Web_Content templates).
 func extractLayoutRef(rawData map[string]any) string {
-	formCall, ok := rawData["FormCall"].(map[string]any)
+	call, ok := rawData["FormCall"].(map[string]any)
+	if !ok {
+		call, ok = rawData["LayoutCall"].(map[string]any)
+	}
 	if !ok {
 		return ""
 	}
 
 	// Try Form field first (string layout name)
-	if formName, ok := formCall["Form"].(string); ok && formName != "" {
+	if formName, ok := call["Form"].(string); ok && formName != "" {
 		return formName
 	}
 
 	// Try Layout field (binary GUID) - extract and format
-	if layoutID := extractBinaryID(formCall["Layout"]); layoutID != "" {
+	if layoutID := extractBinaryID(call["Layout"]); layoutID != "" {
 		return layoutID // Will be a GUID string
 	}
 

mdl/catalog/builder_pages_test.go

@@ -48,6 +48,17 @@ func TestExtractLayoutRef(t *testing.T) {
 			},
 			want: "04030201-0605-0807-090a-0b0c0d0e0f10",
 		},
+		{
+			// Page templates (Forms$PageTemplate) nest the layout under LayoutCall
+			// rather than FormCall.
+			name: "LayoutCall Form field (page template)",
+			rawData: map[string]any{
+				"LayoutCall": map[string]any{
+					"Form": "Atlas_Core.Phone_Default",
+				},
+			},
+			want: "Atlas_Core.Phone_Default",
+		},
 	}
 
 	for _, tt := range tests {