Two new top-level theme.yml keys — nav-section-expand-icon and
nav-section-collapse-icon — replace the hardcoded arrow_right/arrow_drop_down
used on collapsible nav sections. Defaults preserve existing behaviour.
Eight new icon SVGs added to app/assets/icons/:
keyboard_arrow_right / keyboard_arrow_down (chevrons)
keyboard_double_arrow_right / keyboard_double_arrow_down
expand_content / collapse_content (corner arrows)
add / minimize (plus/minus)
All eight added to STANDARD_ICONS so fetch-deps bundles them correctly.
CLAUDE.md key reference and docs/claude-design.md updated with the full
icon catalogue, pairing guidance, and style notes for Claude Design.
https://claude.ai/code/session_01NQKywehSj8Ku4yKhwB4VNB
