duplicate dss dsq key sets built into json

new_targets/tables/lastpricedetail.ms.sql

@@ -166,14 +166,26 @@ WITH exploded_flags AS (
 )
 --SELECT * FROM flag_json
 -- Step 3.4: Nest dss/dsq under each dataseg
+-- Only keep the most recent dss/dsq per dataseg/version (prevents duplicate keys)
 ,seg_pieces AS (
     SELECT
         customer,
         partgroup,
         dataseg,
         STRING_AGG(json_piece, ',') AS inner_json
+    FROM (
+        SELECT sf.*
+        FROM (
+            SELECT *,
+                ROW_NUMBER() OVER (
+                    PARTITION BY customer, partgroup, dataseg, flag
+                    ORDER BY odate DESC, version DESC -- prefer most recent, then prefer 'Actual' over 'Quotes'
+                ) AS rn
             FROM serialized_flags
             WHERE flag IN ('dss', 'dsq')
+        ) sf
+        WHERE sf.rn = 1
+    ) deduped
     GROUP BY customer, partgroup, dataseg
 )
 --SELECT * FROM seg_pieces