feat: complete parliamentary embedding pipeline with full historical coverage

- Add fused (SVD + text) embedding pipeline for annual windows 2016-2026
- Fix store_fused_embedding duplicate bug: DELETE before INSERT (idempotent)
- Add --text-batch-size CLI flag to run_pipeline.py (default 200)
- Add explicit --start-date/--end-date to download_past_year.py
- Backfill mp_votes for all motions (party-level votes, 111k new rows)
- Add similarity cache recompute: 212k rows across 9 annual windows
- Improve ai_provider retry logic, text_pipeline batching
- Improve analysis/political_axis PCA handling and visualizations
- Add diagnostic/utility scripts: compare_svd, generate_compass, inspect_axis, etc.
- Untrack data/motions.db (3.6GB binary), add to .gitignore with outputs/
- Update continuity ledger with full session state

.gitignore

@@ -8,3 +8,12 @@ wheels/
 
 # Virtual environments
 .venv
+
+# Database files (large binary, not suited for git)
+data/*.db
+data/*.bak
+data/*.json
+
+# Generated output files
+outputs/
+outputs_*/