sync localized `chooser` to upstream `v1.3`

[possumbilities]

Description

Includes the following changes:

• feat: add input validation for attribution details chooser#611
• cleanup sections, colors, add EOF in style.css chooser#615
• remove legal contact info from Help section chooser#616
• remove legal contact info from Help section #146
• expand valid year range to currentYear + 5 in Attribution Details chooser#618

Implementation

• I would be interested in implementing this feature.