Populated the right_wing_motions.category column (previously 100% NULL across
3,030 motions) via parallel subagent classification — 80 agents derived a
10-category taxonomy and classified all motions in minutes.
Adds to the Overton QMD report:
- Plotly dropdown filter on Chart 1 to toggle between policy categories
- Chart 7: category delta bar chart (pre/post centrist support per domain)
- Chart 8: quarterly domain trajectories for the 5 largest categories
- Domain Decomposition narrative section
Also fixes a Streamlit tab crash (m.text -> m.body_text) and adds TDD tests.
