Experiment: taxa level (rank) icons

[frewsxcv]

Idea

Experiment with small monochrome icons that visually distinguish each taxonomic rank (the Linnaean "taxa level") wherever a rank is shown in the frontend — taxon detail header, breadcrumb, classification list, and tree panel.

The goal is to make rank scannable at a glance rather than relying on the text label alone.

Sketch of a glyph system

One direction explored in a draft:

• Stacked bars for phylum and above (e.g. 1/2/3 = phylum/kingdom/domain)
• Filled dots arranged on an implied polygon for class → species (5/4/3/2/1 vertices)
• Hollow / gap-split variants for sub-ranks
• Inherit text color via currentColor
• Gracefully fall back to no icon for ranks without a glyph (tribe, super-/infra-, unranked, BOLD identifiers, etc.)

Glyph system reference artifact: https://claude.ai/public/artifacts/87f5a057-5438-49a2-bf65-39f117f43a4a

Open questions

• Is a per-rank glyph actually legible/useful at icon size, or is it noise?
• Dark mode readability (currentColor should follow surrounding text).
• Which surfaces benefit (detail header / breadcrumb / classification list / tree panel) vs. where it's clutter.
• How to handle the long tail of ranks that don't map cleanly to a glyph.

Context

A draft exploration of this lived in #371 (a RankIcon component surfaced across the taxa views). That PR is being closed in favor of tracking the idea here as an experiment rather than carrying an open draft.