Previously the compass (political_axis.py) used hardcoded party sets that
excluded Volt and PvdD, while the SVD components tab (svd_labels.py) used
CANONICAL_LEFT/RIGHT which includes them. This caused inconsistencies in
axis orientation where Volt appeared most left on the compass but PvdD
appeared most left in the SVD components visualization.
Changes:
- Import CANONICAL_LEFT/RIGHT from config in political_axis.py
- Replace hardcoded party sets with CANONICAL_LEFT/RIGHT for axis orientation
- Update tests to match new SVD_THEMES labels