Implement pipe()

Implement solve(fnExprs, initial) where fnExprs is an array of arrow
function expression strings and initial is the starting value.

Apply each function left-to-right, passing the result of each to the next
(like Unix pipes or Array.prototype.reduce).

solve(['x => x + 1', 'x => x * 2', 'x => x - 3'], 5)
→ (5 + 1) * 2 - 3 → 9

Rules

• Compile each expression with new Function('return (' + expr + ';)()')).
• If fnExprs is empty, return initial unchanged.