slides: replace lottery-table slide with two SQL-example slides (win + loss)

Replace the 'lottery in numbers' table with two slides, each showing
the actual SQL of one ClickBench query:

  - Slide 3 'When pushdown wins big': Q23 (SELECT * ... WHERE URL LIKE
    '%google%' ... LIMIT 10), main 3 612 ms → +pd 121 ms, 30× faster.
  - Slide 4 'When pushdown loses big': Q30 (... WHERE SearchPhrase <> ''
    GROUP BY ...), main 276 ms → +pd 547 ms, 1.98× slower.

Both queries hit the same ClickBench dataset — same flag, opposite
outcomes. Speaker notes give the mechanism: row-level eval + sparse
RowSelection → page-skipping (win) vs mandatory unselective filter
with no row-skipping payoff and an extra column read (loss).

Renumber slide-comment headers to keep them sequential (1..10).

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: adriangb