refactor: move shouldMergeObjects from rawpaths to heuristics

tools/jsontypes/heuristics.go

@@ -382,6 +382,40 @@ func capitalize(s string) string {
 }
 
 // singularize does a naive singularization for common English plurals.
+// shouldMergeObjects decides whether a pool of objects should be treated as
+// one struct type with optional fields, rather than multiple distinct types.
+//
+// Heuristic: if ≥ 2 keys appear in more than half the objects, the objects
+// likely share a common shape with optional fields. This catches the common
+// case of API responses where every record has the same core fields but some
+// records have extra ones (e.g. pagination results).
+func shouldMergeObjects(objects []map[string]any) bool {
+	n := len(objects)
+	if n < 2 {
+		return false
+	}
+
+	// Count how many objects contain each key.
+	keyCount := make(map[string]int)
+	for _, obj := range objects {
+		for k := range obj {
+			keyCount[k]++
+		}
+	}
+
+	// Count keys that appear in a majority of objects.
+	threshold := n / 2
+	highFreq := 0
+	for _, count := range keyCount {
+		if count > threshold {
+			highFreq++
+		}
+	}
+
+	// Two or more high-frequency keys means the objects share a common core.
+	return highFreq >= 2
+}
+
 func singularize(s string) string {
 	// Uncountable / already-singular words ending in -s.
 	switch strings.ToLower(s) {

tools/jsontypes/rawpaths.go

@@ -370,36 +370,4 @@ func joinPath(prefix, field string) string {
 	return prefix + "." + field
 }
 
-// shouldMergeObjects decides whether a pool of objects should be treated as
-// one struct type with optional fields, rather than multiple distinct types.
-//
-// Heuristic: if ≥ 2 keys appear in more than half the objects, the objects
-// likely share a common shape with optional fields. This catches the common
-// case of API responses where every record has the same core fields but some
-// records have extra ones (e.g. pagination results).
-func shouldMergeObjects(objects []map[string]any) bool {
-	n := len(objects)
-	if n < 2 {
-		return false
-	}
 
-	// Count how many objects contain each key.
-	keyCount := make(map[string]int)
-	for _, obj := range objects {
-		for k := range obj {
-			keyCount[k]++
-		}
-	}
-
-	// Count keys that appear in a majority of objects.
-	threshold := n / 2
-	highFreq := 0
-	for _, count := range keyCount {
-		if count > threshold {
-			highFreq++
-		}
-	}
-
-	// Two or more high-frequency keys means the objects share a common core.
-	return highFreq >= 2
-}