Snapshot specs 33_meta/17, 18, 26 (.debug plans) fail on main since #254's join-planner change #290

Found by the EN-15 lane while rebasing: three query-plan snapshot specs (33_meta/17, 33_meta/18, 33_meta/26, .debug plan output) fail on main since the join-planner change in #254. CI's full suite is green, so these specs are not in the CI gate. Fix: confirm the new plans are correct, update the snapshots (or fix the planner if a plan regressed), and add these specs to CI so plan output is gated.