Cross-Chain Portfolio Reconciler

Builds a provider per chain from the built-in network list, so all seven are read simultaneously without switching networks in your wallet. Groups balances by token symbol, making clear that the same asset bridged onto five chains is five separate contracts rather than one balance seen repeatedly. Also reports native balances per chain and flags any chain holding tokens but too little gas to move them — the most common way funds end up stranded. Reads each chain through its own public endpoint, so no network switching is needed, but a rate-limited endpoint will return an error for that chain rather than a wrong number. Token addresses are yours to supply — the same asset has a different contract on every chain it has been bridged to.