fix(compass): fix annual window detection in get_uniform_dim_windows

Previous query used DISTINCT ON without ordering by dim, picking arbitrary
(often non-50) dim per window. Rewritten to find the dominant dim per window
(highest count) and include only windows where dominant dim = 50 with >= 10
entities. This surfaces annual windows 2016/2018/2019/2022-2026 that were
previously excluded due to mixed-dim rows from multiple pipeline runs.

explorer.py

@@ -118,34 +118,37 @@ def get_available_windows(db_path: str) -> List[str]:
 
 @st.cache_data(show_spinner=False)
 def get_uniform_dim_windows(db_path: str) -> List[str]:
-    """Return only windows whose vector dimension equals the most common dimension.
+    """Return only windows whose dominant MP-vector dimension is 50.
 
-    np.vstack requires all vectors to have the same shape. Early or small windows
-    have lower SVD rank (dim < 50). This helper filters to only windows at the
-    dominant (max-count) dimension so compute_2d_axes never sees mixed shapes.
+    Some windows contain a mix of vector lengths due to multiple pipeline runs
+    (e.g. 2016 has both dim=1 and dim=50 rows). We find the most common dimension
+    per window and include only windows where that dominant dim equals 50.
+    Windows with too few dim-50 entities (< 10) are also excluded to avoid
+    degenerate PCA inputs.
     """
     con = duckdb.connect(database=db_path, read_only=True)
     try:
         rows = con.execute(
             """
-            WITH window_dims AS (
-                SELECT DISTINCT ON (window_id)
-                    window_id,
-                    json_array_length(vector) AS dim
+            WITH vec_dims AS (
+                SELECT window_id, json_array_length(vector) AS dim
                 FROM svd_vectors
                 WHERE entity_type = 'mp'
-                ORDER BY window_id
             ),
-            dim_counts AS (
-                SELECT dim, COUNT(*) AS cnt FROM window_dims GROUP BY dim
+            window_dim_counts AS (
+                SELECT window_id, dim, COUNT(*) AS cnt
+                FROM vec_dims
+                GROUP BY window_id, dim
             ),
             dominant AS (
-                SELECT dim FROM dim_counts ORDER BY cnt DESC, dim DESC LIMIT 1
+                SELECT DISTINCT ON (window_id) window_id, dim, cnt
+                FROM window_dim_counts
+                ORDER BY window_id, cnt DESC, dim DESC
             )
-            SELECT wd.window_id
-            FROM window_dims wd
-            JOIN dominant d ON wd.dim = d.dim
-            ORDER BY wd.window_id
+            SELECT window_id
+            FROM dominant
+            WHERE dim = 50 AND cnt >= 10
+            ORDER BY window_id
             """
         ).fetchall()
         return [r[0] for r in rows]