🦙Tina - Add ISR for content changes

CC: @wicksipedia, @miichaelsmedley

The Pain

Changes made using Tina cannot be previewed (outside of the Tina editor). Until the branch has been re-deployed. This can result in confusion.

Solution

We should investigate using ISR so that static routes using Tina are rebuilt when data is updated in Tina Cloud

Option 1: Use on-demand webhooks to invalidate the cache after saving

Note: Tina may not have webhook support yes, discuss this with Wicksy/someone from the Tina team
https://vercel.com/templates/next.js/on-demand-incremental-static-regeneration
https://nextjs.org/docs/app/building-your-application/data-fetching/incremental-static-regeneration#on-demand-revalidation-with-revalidatepath

Option 2: Time based revalidation (not recommended)

https://nextjs.org/docs/app/building-your-application/data-fetching/incremental-static-regeneration#time-based-revalidation

Figure: outdated page being shown while staging branch rebuilds

Start with the Tina Cloud save flow and the site's Next.js static route generation, then review the linked Next.js ISR and revalidatePath documentation. Confirm whether Tina supports on-demand webhooks and choose an invalidation approach; done means Tina content changes appear on static routes without a branch redeploy.