Fix multi-level nested scalar subquery evaluation

[Copilot]

Nested scalar subqueries deeper than two levels failed at runtime because inner selects resolved queriesidx against a missing queriesfn.

Changes

• compileQueries: share the compiled subquery list down the tree so multi-level scalar selects can resolve this.queriesfn[queriesidx - 1]
• Nested IN path: avoid overwriting a queriesfn already built during nested compile()
• test/test1025.js: regression coverage for 2–4 level scalar nesting, derived tables, and nested scalars inside IN

Example

-- previously threw: Cannot read properties of undefined (reading '0')
SELECT (SELECT (SELECT 1 AS c) AS b) AS a;
-- => [{ a: 1 }]

• Fixes Third level of subquery result in error #1025