Added support for viewing available structures. Created Structure and Structures components to display buildable structures at locations. The API layer now fetches available structure data and caches it in localStorage.

Improved trade route determination to use the pathfinding graph directly. The determineBestTradeRoute function now considers multi-hop routes when calculating profitability. Added a Route type to better structure path data.

Organized localStorage usage with a central Keys module for consistent key naming. Added error count display in the UI to track API failures.

Various stability fixes including null checks, routing fixes, and initialization improvements. Increased max cargo per trade to 500 and created a custom useInterval hook to replace the external dependency.