mermaid diagrams are hard to see in dark mode

[willmurphyscode]

The brightness on my monitor is too high, so I view all sites in dark mode. In dark mode, on https://oss-docs.pages.dev/docs/architecture/ for example, the mermaid diagrams are pretty hard to see:

Dark mode screenshot:

Contrast that with light mode screen shot:

[wagoodman]

Part of this has to do with this patch. When the page loads it starts with the theme in the "auto" selection, then dynamically changes to either dark or light based on previous selections. The mermaid code does not know how to handle this, so upstream code simply calls reload() which should reinitialize the diagram and load it with the right theming.

The downside is when deployed to cloudflare (for some reason) a race condition appears where the entire page keeps infinitely reloading, caused by this single line. I hit my timebox troubleshooting the issue and decided a working site with light mode was better than a non-working site with both dark and light mode.

I was not able to reproduce the issue reliably when deployed locally with make dev, or if I did a build and served it up locally (or if I added network throttling and CPU delays). The only way I was able to really debug this was with a PR branch that I was continually pushing to and then navigating to a page on the preview link with a mermaid diagram.