Replace the simple open/closed disclosure arrows with full spanning
tree branch connectors that draw pipe-style lines between parent and
child items in the model tree.
New dark-theme SVGs created with Catppuccin colors:
- branch_vline_dark: vertical continuation line (#585b70)
- branch_more_dark: T-junction for mid-siblings
- branch_end_dark: L-junction for last sibling
- branch_more_closed_dark: T-junction + closed chevron (#a6adc8)
- branch_more_open_dark: T-junction + open chevron (#cdd6f4)
- branch_end_closed_dark: L-junction + closed chevron
- branch_end_open_dark: L-junction + open chevron
Updated QSS branch pseudo-selectors in KindredCreate.qss to map all
seven branch states (vline, more, end, more-closed, more-open,
end-closed, end-open) to the corresponding SVGs.
Updated ztools submodule with matching CatppuccinMocha.qss changes.
0d4545b7d6