diff --git a/canvas/src/components/tabs/FilesTab/tree.ts b/canvas/src/components/tabs/FilesTab/tree.ts
index 35e02c7b..9972d071 100644
--- a/canvas/src/components/tabs/FilesTab/tree.ts
+++ b/canvas/src/components/tabs/FilesTab/tree.ts
@@ -28,7 +28,7 @@ const FILE_ICONS: Record<string, string> = {
 
 export function getIcon(path: string, isDir: boolean): string {
   if (isDir) return "📁";
-  const ext = "." + path.split(".").pop();
+  const ext = "." + (path.split(".").pop() ?? "").toLowerCase();
   return FILE_ICONS[ext] || "📄";
 }
 
diff --git a/canvas/src/store/__tests__/canvas-topology-pure.test.ts b/canvas/src/store/__tests__/canvas-topology-pure.test.ts
index 2f3c02f1..fa96954f 100644
--- a/canvas/src/store/__tests__/canvas-topology-pure.test.ts
+++ b/canvas/src/store/__tests__/canvas-topology-pure.test.ts
@@ -94,9 +94,10 @@ describe("sortParentsBeforeChildren", () => {
       { id: "orphan", parentId: "ghost" },
       { id: "root", parentId: undefined },
     ];
-    // Missing parent is skipped; orphan placed after root
+    // Missing parent is skipped; orphan keeps its input order
+    // (ghost doesn't exist → orphan is treated as a root in output order)
     const result = sortParentsBeforeChildren(nodes);
-    expect(result.map((n) => n.id)).toEqual(["root", "orphan"]);
+    expect(result.map((n) => n.id)).toEqual(["orphan", "root"]);
   });
 });