src/node/routes/vscode.ts/CodeServerRouteWrapper/manifest
class CodeServerRouteWrapper:  private manifest: express.Handler = async (req, res, next) => {
    const appName = req.args["app-name"] || "code-server"
    res.writeHead(200, { "Content-Type": "application/manifest+json" })

    return res.end(
      replaceTemplates(
        req,
        JSON.stringify(
          {
            name: appName,
            short_name: appName,
            start_url: ".",
            display: "fullscreen",
            description: "Run Code on a remote server.",
            icons: [192, 512].map((size) => ({
              src: `{{BASE}}/_static/src/browser/media/pwa-icon-${size}.png`,
              type: "image/png",
              sizes: `${size}x${size}`,
            })),
          },
          null,
          2,
        ),
      ),
    )
  }