fix: use aligned PCA positions for SVD components 1-2 (consistent with compass)

Previously the SVD components tab used raw SVD scores while the compass
used Procrustes-aligned PCA positions. This caused party orderings to
differ between the two visualizations.

Changes:
- Components 1-2 now use aligned positions from load_positions()
  (same as compass) for consistent party ordering
- Components 3-10 continue to use raw SVD scores
- Added _get_aligned_party_coords() helper to convert aligned MP
  positions to party centroids

explorer.py

@@ -2410,6 +2410,9 @@ def build_svd_components_tab(db_path: str) -> None:
 
     Reads thoughts/explorer/top_svd_top_motions.json and displays a selector
     for components 1..10 with theme labels/explanations and a detail pane per motion.
+
+    Components 1-2 use aligned PCA positions (consistent with compass).
+    Components 3-10 use raw SVD scores.
     """
     st.subheader("🔬 SVD Assen — politieke polarisatiethema's")
     st.markdown(
@@ -2556,7 +2559,7 @@ def build_svd_components_tab(db_path: str) -> None:
             key=f"svd_window_{comp_sel}",
         )
 
-    # Load party scores for the selected window
+    # Load party scores for the selected window (used for components 3-10)
     if svd_window == "current_parliament":
         party_scores = party_scores_default
     else:
@@ -2567,6 +2570,55 @@ def build_svd_components_tab(db_path: str) -> None:
         {p: len(v) for p, v in party_mp_vectors.items()} if party_mp_vectors else {}
     )
 
+    # For components 1-2, use aligned positions from load_positions (same as compass)
+    # for consistency. For components 3-10, use raw SVD scores.
+    def _get_aligned_party_coords(window: str) -> Dict[str, Tuple[float, float]]:
+        """Get party (x, y) coordinates from aligned PCA positions for a window."""
+        positions_by_window, _ = load_positions(db_path, "annual")
+        window_pos = positions_by_window.get(window, {})
+        if not window_pos:
+            return {}
+
+        # Load party map to convert MP names to parties
+        _party_map = load_party_map(db_path)
+
+        # Aggregate MP positions to party centroids
+        party_coords: Dict[str, List[Tuple[float, float]]] = {}
+        for mp_name, (x, y) in window_pos.items():
+            party = _party_map.get(
+                mp_name, _party_map.get(mp_name.split("(")[0].strip(), None)
+            )
+            if party:
+                party_coords.setdefault(party, []).append((x, y))
+
+        # Compute mean position per party
+        return {
+            party: (
+                float(np.mean([c[0] for c in coords])),
+                float(np.mean([c[1] for c in coords])),
+            )
+            for party, coords in party_coords.items()
+            if coords
+        }
+
+    # Extract 1D scores for this component
+    party_1d_coords: dict = {}
+
+    if comp_sel <= 2:
+        # Components 1-2: use aligned PCA positions from load_positions (consistent with compass)
+        aligned_coords = _get_aligned_party_coords(svd_window)
+        for party, (x, y) in aligned_coords.items():
+            party_1d_coords[party] = (x,) if comp_sel == 1 else (y,)
+    else:
+        # Components 3-10: use raw SVD scores
+        idx = comp_sel - 1  # Convert to 0-indexed
+        for party, scores in party_scores.items():
+            try:
+                if scores and len(scores) > idx:
+                    party_1d_coords[party] = (float(scores[idx]),)
+            except Exception:
+                continue
+
     # Auto-compute flip directions for ALL components 1-10 based on party centroids.
     # Each window's SVD has arbitrary sign orientation, so we compute flip per component
     # to ensure canonical right parties (PVV, FVD, JA21, SGP) appear on the RIGHT.
@@ -2587,16 +2639,6 @@ def build_svd_components_tab(db_path: str) -> None:
         "flip": computed_flips.get(comp_sel, theme.get("flip", False)),
     }
 
-    # Extract 1D scores for this component (ALL components use raw SVD values)
-    party_1d_coords: dict = {}
-    idx = comp_sel - 1  # Convert to 0-indexed
-    for party, scores in party_scores.items():
-        try:
-            if scores and len(scores) > idx:
-                party_1d_coords[party] = (float(scores[idx]),)
-        except Exception:
-            continue
-
     # Filter parties by minimum MP count
     if min_mps > 1 and party_mp_counts:
         valid_parties = {p for p, count in party_mp_counts.items() if count >= min_mps}
@@ -2615,10 +2657,9 @@ def build_svd_components_tab(db_path: str) -> None:
         has_current = "current_parliament" in available_windows
         all_windows = year_windows + (["current_parliament"] if has_current else [])
 
-        # ALL components use raw (non-aligned) SVD vectors.
+        # For components 1-2, use aligned PCA positions for consistency with compass.
-        # Procrustes alignment rotates the full vector space which makes scores
+        # For components 3-10, use raw SVD scores.
-        # incomparable with the single-window view. Per-window flip computation
+        # Per-window flip computation handles orientation alignment for the trajectory.
-        # handles orientation alignment for the trajectory.
         party_scores_by_window = load_party_scores_all_windows(db_path, all_windows)
 
         _render_svd_time_trajectory(