Removes embedding-heavy search and generic browser tabs from the Explorer.
The project does not currently use embeddings meaningfully, so the similarity
search and browser features were dead weight.
Changes:
- explorer.py: Remove search and browser tabs, keep compass/trajectories/SVD
- explorer.py: Remove fused_embeddings and similarity_cache stats from sidebar
- Home.py: Update Explorer description to match new focused layout
- analysis/tabs/__init__.py: Remove search and browser exports
- tests: Update decomposition and import tests for new tab set
Result: Explorer now has 3 focused analytical tabs instead of 5.
- Rename app to 'Motief: de stematlas' in Home.py
- Remove PCA variance caption from compass tab
- Hardcode db_path and window_size; remove sidebar inputs
- Change trajectories default to [CDA, D66, VVD]
- Move quiz to pages/1_Stemwijzer.py; wrap in st.form
- Remove quiz tab from main explorer
- Add pytest dev dep + fix test fixtures (_load_mp_vectors_for_window)
- Add test_pca_axis_orientation with proper PCA variance dominance