WINDOW                                     AGGREGATE        ROW SUM          ROWS      RESULT
--------------------------------------------------------------------------------------------------------
Jul-Aug 2026 (verified in Round 8)         4,716.00         4,716.00         72        MATCH
Jun 2026                                   3,200.00         3,200.00         55        MATCH
2025                                       349,606.35       349,606.35       3585      MATCH
max-only - the range that used to fatal    2,091,227.60     2,091,227.60     32526     MATCH

peak memory: 1685 MB

The aggregate equals the row sum in every window - the optimisation changes speed, not arithmetic.