🚀 Feature request

Add a marker for SSR pages.

Description

We'd want to easily detect which pages are server-side rendered in HTTPArchive.

Describe the solution you'd like

Add a marker in an attribute.

Describe alternatives you've considered

Currently, we can easier distinguish between SSR, SSG, and client-side apps (CSR) by:

• SSG adds a comment saying the page is prerendered
• SSR output looks different than CSR apps but it's harder to query in HTTPArchive which seem to primarily allow queries over the final output, after hydration

// cc @kara @jelbourn