Returns the ETH balance of a supplied Base address via eth_getBalance; takes address (0x + 40 hex).

GET https://ari001.tailb4ac3a.ts.net/v1/ventures/x402_chain_reads_v1/base_wallet_1. Same payment terms as that HTTP route. Call once with no payment. The result is the payment terms. Retry the same call with the signed payment at _meta["x402/payment"]. Measured output: {"chain": "base", "hex": "0x0", "method": "eth_getBalance", "ok": true, "result": 0, "service": "x402_chain_reads_v1.base_eth_getbalance"}