The four-line description above the heatmap was concise but
opaque: 'X: log10 €/year. Y: 0–5. Punktgröße.' said the right
words, but a reviewer who isn't already methodologically
oriented can't tell what they're looking at.
Adds a dedicated Legende-Karte directly under the heatmap.
Four rows, each: leading symbol (↔ ↕ ● ◐), axis-or-quantity
label, prominent name (Schaden / Nutzen / Betroffenheit /
Evidenz-Stufe), and a short prose explanation tying the visual
back to the Studie:
↔ Abszisse (X) Schaden — log10 €/Jahr, SKM §3.1
↕ Ordinate (Y) Nutzen — 7-dim. Komposit §3.2
● Punktgröße Betroffenheit — sqrt scale, DESTATIS-/IHK
◐ Tier-Farbe Evidenz-Stufe — Regel der niedrigsten §6.7
Top description tightened to one line of context only:
'Schaden × Nutzen × Betroffenheit pro Norm. Klick auf einen
Punkt öffnet das Detail …'. No redundancy with the legend,
no jargon up top.
Signed-off-by: flemming-it <sf@flemming.it>