When on /trading/engine, the /trading nav item also matched via
startsWith. Now checks if a more specific child route matches
first and uses exact match in that case.
TypeScript strict mode in CI rejects explicit parameter types on
Recharts formatter/tickFormatter callbacks. Use inference with
'as number' casts on the value instead. Also fix unsafe cast in
PortfolioComposition and handle possibly-undefined percent.
Celes Renata