CHange the handling of static files:
- The entire `static/` directory is now compiled into the binary, not just specific files.
- The server serves static files from an in-memory table instead of reading from disk.
- The static files are linked by their paths under `/static/` in the HTML template.
  - This includes the `/static/` part of the path
- The intention is that static assets can reference each other using relative paths. (e.g. CSS referencing images)
- The `www/` directory remains for user uploads, served from disk.