Placemark updates

I had a bit of energy to work on Placemark last night:

• I set up Renovate to do automated dependency updates once a month, and fixed about 70% of the update debt.
• I used Knip to find unused files & dependencies and removed them. This was a pretty enormous cut in both application size & node_modules weight. A lot of dependencies had been left danging after the removal of the the SaaS-oriented bits of Placemark.

Simplification is the goal: I want Placemark to be approachable, installable, and adaptable.

I'm totally into merging PRs for this project for any kind of improvement. For myself, I'm thinking about:

• Replacing Next.js (a React framework and bundler with lots of bells and whistles) with Vite (just a bundler). I'm not using really any features from Next.js, and it would be nice to simplify.
• Updating mapbox-gl-js and possibly replacing it or making it swappable with Maplibre. This would make the whole dependency tree compliant open-source.
• Making part of the map editing modular as a component, so it could be reused more easily. This is kind of a tall order in the most maximal version - map editing is a very cross-cutting concern - but I think it would unlock a lot of new usecases. I really admire Markwhen, which is in a way a similar tool for editing a custom data format, and it does this pretty well, making the editor experience usable outside of the reference apps.