Debug-log every API request and response

Add debugFetch wrapper in log.js that logs method, URL, and body on
request, and status code on response. Replace all fetch() calls
across balances, transactions, tokens, background RPC proxy, and
settings validation with debugFetch.

src/shared/tokens.js

@@ -5,6 +5,8 @@
 // Source: Etherscan, CoinGecko, CoinMarketCap as of 2026-02-25.
 // Ordered by approximate market cap descending.
 
+const { debugFetch } = require("./log");
+
 const COINDESK_API = "https://data-api.coindesk.com/index/cc/v1/latest/tick";
 
 const DEFAULT_TOKENS = [
@@ -818,7 +820,7 @@ async function getTopTokenPrices(n) {
         "?market=cadli&instruments=" +
         instruments +
         "&apply_mapping=true";
-    const resp = await fetch(url);
+    const resp = await debugFetch(url);
     const json = await resp.json();
     const prices = {};
     for (const [instrument, data] of Object.entries(json.Data || {})) {