Dont cache index.html in nginx config

[Phillezi]

Fix SPA breakage due to cached index.html

• Ensure index.html is never cached by the browser to prevent serving outdated HTML that references old JS/CSS bundles.

  • Added Cache-Control: no-cache, no-store, must-revalidate and expires -1 for .html files in Nginx.

• Temporary workaround for existing clients with the old index.htmlcached:

  • Create a symlink from the new JS bundle to the filename of the old bundle.
  • This allows clients requesting the old JS file (from cached HTML) to still load the latest code without seeing a white screen.

closes #356

[Phillezi]

Will change the cache policy for index.html in a later pr