Feature bloat in side menus

As more features are added, it is no longer feasible to keep adding new blocks into the side menus. Proposed solutions:

- Add an analysis tab for future analysis functions
- Make side menu groups collapsable, and collapse all but the essential functionality by default
- Move our category editing from the side menu, OR make category editing "swap out" the entire side menu

The issue identifies side menus and category editing as the affected areas but names no files, tests, or entry points. First inspect the side-menu implementation and existing navigation behavior, then clarify which proposed direction is intended; done should mean a decided, implemented menu structure that accommodates future features without continued menu bloat.

Written by the indexing model from the issue text.