fix: make codegen not fail for "blob" columns

- was previously using "[]byte" as a single `ast.NewIdent`, which made comment+blank-line-insertion reparsing fail

pkg/codegen/modelgenerate/ast_helpers.go

@@ -76,28 +76,35 @@ func FprintWithComments(w io.Writer, file *ast.File) error {
 		return fmt.Errorf("re-parsing pretty-print: %w", err)
 	}
 
-	// Convert the tree-of-nodes into a slice-of-nodes
-	collectNodes := func(node ast.Node) []ast.Node {
-		var nodes []ast.Node
-		ast.Inspect(node, func(n ast.Node) bool {
-			// Filter out comments, as they only appear in the
-			switch n.(type) {
-			case *ast.CommentGroup, *ast.Comment:
-				return false
-			}
-			nodes = append(nodes, n)
-			return true
-		})
-		return nodes
-	}
-
 	// Parallel walk: apply TrailingComments from the side map.
 	// Both trees have identical structure (the reparse is just a positioned copy),
 	// so ast.Inspect visits nodes in the same order.  We skip comment nodes to
 	// avoid mismatches from Doc fields.
 	if len(TrailingComments) > 0 {
+		// Helper: convert the tree-of-nodes into a slice-of-nodes
+		collectNodes := func(node ast.Node) []ast.Node {
+			var nodes []ast.Node
+			ast.Inspect(node, func(n ast.Node) bool {
+				// Filter out comments, as they only appear in the
+				switch n.(type) {
+				case *ast.CommentGroup, *ast.Comment:
+					return false
+				}
+				nodes = append(nodes, n)
+				return true
+			})
+			return nodes
+		}
+
 		origNodes := collectNodes(file)
 		reparsedNodes := collectNodes(parsed)
+		if len(origNodes) != len(reparsedNodes) {
+			panic(fmt.Sprintf(
+				"origNodes: %d; reparsedNodes: %d.  The AST generator is likely generating an invalid AST",
+				len(origNodes), len(reparsedNodes),
+			))
+		}
+
 		for i, orig := range origNodes {
 			text, isOk := TrailingComments[orig]
 			if !isOk {