CoinPay Wallet Extension v0.6.1 — correct balances and total

Fixed The wallet under-reported its own balance. A chain holds one balance row per derivation index — the web wallet issues a fresh receiving address each time it's asked — so funds accumulate across indexes. The extension keyed assets by chain and overwrote instead of summing, showing whichever row came last. On a real wallet that meant SOL displayed 0.1757 when the account actually held 0.3245…