fix(webui): use portal file reference tooltips

webui/src/tests/message-bubble.test.tsx

@@ -1,4 +1,4 @@
-import { fireEvent, render, screen, waitFor } from "@testing-library/react";
+import { act, fireEvent, render, screen, waitFor } from "@testing-library/react";
 import { describe, expect, it, vi } from "vitest";
 
 import { MessageBubble } from "@/components/MessageBubble";
@@ -179,6 +179,47 @@ describe("MessageBubble", () => {
     expect(screen.getByText("Body line.")).toBeInTheDocument();
   });
 
+  it("renders inline file paths as compact file references", async () => {
+    await import("@/components/MarkdownTextRenderer");
+    const message: UIMessage = {
+      id: "a-file-path",
+      role: "assistant",
+      content:
+        "改动在 `webui/src/components/MarkdownTextRenderer.tsx` 和 `/Users/renxubin/.nanobot/workspace/minecraft-fps/index.html`。",
+      createdAt: Date.now(),
+    };
+
+    try {
+      render(<MessageBubble message={message} />);
+
+      const references = await screen.findAllByTestId("inline-file-path");
+      expect(references).toHaveLength(2);
+      expect(references[0].parentElement).not.toHaveClass("translate-y-[0.08em]");
+      expect(references[0].parentElement).toHaveClass("align-[0.14em]");
+      expect(references[0]).toHaveTextContent("MarkdownTextRenderer.tsx");
+      expect(references[0]).not.toHaveTextContent("webui/src/components");
+      expect(screen.getByText("index.html")).toBeInTheDocument();
+      expect(references[1]).not.toHaveTextContent("/Users/renxubin");
+      expect(references[1]).not.toHaveAttribute("title");
+      expect(references[1]).toHaveAttribute(
+        "aria-label",
+        "/Users/renxubin/.nanobot/workspace/minecraft-fps/index.html",
+      );
+
+      vi.useFakeTimers();
+      fireEvent.pointerMove(references[1].parentElement!);
+      await act(async () => {
+        vi.advanceTimersByTime(500);
+      });
+      const tooltip = screen.getByRole("tooltip");
+      expect(tooltip).toHaveTextContent(
+        "/Users/renxubin/.nanobot/workspace/minecraft-fps/index.html",
+      );
+    } finally {
+      vi.useRealTimers();
+    }
+  });
+
   it("renders assistant image media as a larger generated result", () => {
     const message: UIMessage = {
       id: "a-image",