Align Chapter 3 Figure 7 boxes

[restful3]

Summary

• align the Disease A box exactly with the phenotype box above it
• align the 상위 범주 질의 box exactly with the Goiter box above it
• make both lower boxes use the same 252-unit width and matching left/right edges
• recenter the labels and update direct/inferred connectors for the new geometry

Why

The lower boxes used different widths and protruded beyond the boxes immediately above them, creating an unintended visual imbalance.

Validation

• SVG XML validation and git diff --check
• required index and site validation scripts passed
• geometry measured: upper/lower pairs are exactly 68..320 and 594..846
• direct Figure 7 render and slide 20 inspected at 1280×720
• all 27 slides passed at desktop and mobile viewports; report images passed at desktop/mobile widths