feat: re-enable code splitting

[SgtPooki]

• feat: add code splitting back
• chore: debugging
• chore: debugging
• chore: debugging
• fix: firefox properly replaces old service worker

To debug this, follow this process:

npm run clean && npm run start
# load the page

# if you need to reload the old SW...
git checkout main
npm run clean && npm run start
# load the page

git checkout fix/splitting-sw
npm run clean && npm run start
# load the page

# repeat as needed

[SgtPooki]

not sure why chrome is failing here.. we can address when code-splitting becomes a priority again

[2color]

Do you have any rough numbers on the size of bundle before/after? This can probably help us evaluate the benefit we get out of code splitting.