Remove `react-dom/server` from client bundle in `inline-mention-editor.tsx`

[MODSetter]

Description

inline-mention-editor.tsx statically imports react-dom/server (line 13) to use renderToString for creating two small DOM elements (a connector icon and an X close button in mention chips). This pulls the entire server rendering runtime into the client-side JavaScript bundle.

This module is imported by thread.tsx, which is the main chat component — so react-dom/server is loaded on every chat page load.

File to change

• surfsense_web/components/assistant-ui/inline-mention-editor.tsx

Current code

Line 13 (import):

import ReactDOMServer from "react-dom/server";

Lines 216-218 (connector icon):

iconSpan.innerHTML = ReactDOMServer.renderToString(
    getConnectorIcon(doc.document_type ?? "UNKNOWN", "h-3 w-3")
);

Lines 225-227 (close button X icon):

removeBtn.innerHTML = ReactDOMServer.renderToString(
    createElement(X, { className: "h-3 w-3", strokeWidth: 2.5 })
);

What to do

Replace ReactDOMServer.renderToString with client-side rendering. A safe approach:

import { createRoot } from "react-dom/client";
import { flushSync } from "react-dom";

function renderToHTML(element: React.ReactElement): string {
  const container = document.createElement("div");
  const root = createRoot(container);
  flushSync(() => root.render(element));
  const html = container.innerHTML;
  root.unmount();
  return html;
}

Then replace both usages:

iconSpan.innerHTML = renderToHTML(
    getConnectorIcon(doc.document_type ?? "UNKNOWN", "h-3 w-3")
);

removeBtn.innerHTML = renderToHTML(
    createElement(X, { className: "h-3 w-3", strokeWidth: 2.5 })
);

react-dom and react-dom/client are already in the client bundle (used by React itself), so createRoot + flushSync add zero new bundle weight.

Important: After making changes, test that:

• Mention chips display the correct connector icon
• The X close button appears on hover
• Clicking X removes the chip
• All connector types show correct icons

Acceptance criteria

• react-dom/server is NOT imported anywhere in inline-mention-editor.tsx
• Mention chip icons still render correctly
• Chip remove (X) button still works
• next build succeeds