chore: bring the token-list enrichment tooling into script/lib (closes #495)

The two node programs and the data file from f7a2437 regenerate the name and
url of each token in src/shared/tokenList.js. They are now CommonJS under
script/lib/ and read ethereum-lists at a pinned commit. The apply step also
rewrites an entry that already has a name and url, so it runs on the current
list, and stops on an address that matches no list entry. Exported as
applyEnrichment, it is run by tests/applyEnrichment.test.js, which fails when
the committed list differs from what it writes. Its table of websites now gives
FLOKI and TURBO a URL. make enrich-tokens and make apply-enrichment run the
programs. script/check-censored allows the MUSD token's on-chain name in the
data file.

Model: opus-5-5

script/lib/enrich-tokens.js

@@ -0,0 +1,115 @@
+// Fetches a name and a website for every token in src/shared/tokenList.js and
+// writes them, keyed by address, to script/lib/token-enrichment.json, which
+// script/lib/apply-enrichment.js then writes into tokenList.js. Run by
+// `make enrich-tokens`; no build runs it and nothing here is shipped.
+//
+// Names come from CoinGecko's coin list, fetched whole in one request, matched
+// on the token's Ethereum contract address. A token CoinGecko does not list
+// gets its symbol as its name. The list is live data with no fixed version, so
+// a later run can return different names.
+//
+// Websites come from the ethereum-lists/tokens repository, one file per token,
+// read at a pinned commit. Most tokens have no file there and get an empty URL.
+// A file that is missing is not an error; any other failed request stops the
+// run, so a network fault cannot quietly empty a URL.
+
+"use strict";
+
+const fs = require("fs");
+const path = require("path");
+
+const TOKEN_LIST = path.join(__dirname, "..", "..", "src/shared/tokenList.js");
+const OUTPUT = path.join(__dirname, "token-enrichment.json");
+
+const COINGECKO_LIST =
+    "https://api.coingecko.com/api/v3/coins/list?include_platform=true";
+// ethereum-lists/tokens at its master of 2026-02-27, when the committed
+// token-enrichment.json was made.
+const ETHEREUM_LISTS =
+    "https://raw.githubusercontent.com/ethereum-lists/tokens/c3560d499a380a38e94caa7c4968d59aeffde59a/tokens/eth";
+
+const CONCURRENT = 10;
+
+const sleep = (ms) => new Promise((r) => setTimeout(r, ms));
+
+async function main() {
+    const src = fs.readFileSync(TOKEN_LIST, "utf8");
+
+    const tokens = [];
+    const re =
+        /\{\s*address:\s*"(0x[a-fA-F0-9]{40})",\s*symbol:\s*"([^"]+)",\s*decimals:\s*(\d+)/g;
+    let m;
+    while ((m = re.exec(src)) !== null) {
+        tokens.push({ address: m[1], symbol: m[2], decimals: parseInt(m[3]) });
+    }
+    console.error(`Parsed ${tokens.length} tokens`);
+
+    // --- Names from CoinGecko ---
+    console.error("Fetching CoinGecko coins list...");
+    const listResp = await fetch(COINGECKO_LIST);
+    if (!listResp.ok) throw new Error(`CoinGecko list HTTP ${listResp.status}`);
+    const coins = await listResp.json();
+
+    const addrMap = new Map();
+    for (const coin of coins) {
+        const eth = (coin.platforms?.ethereum || "").toLowerCase().trim();
+        if (eth && eth.startsWith("0x")) {
+            addrMap.set(eth, { name: coin.name, id: coin.id });
+        }
+    }
+    console.error(`CoinGecko map: ${addrMap.size} Ethereum tokens`);
+
+    const enriched = new Map();
+    let namesMatched = 0;
+    for (const t of tokens) {
+        const info = addrMap.get(t.address.toLowerCase());
+        if (info) namesMatched++;
+        enriched.set(t.address, { name: info?.name || t.symbol, url: "" });
+    }
+    console.error(`Matched ${namesMatched}/${tokens.length} names`);
+
+    // --- Websites from ethereum-lists ---
+    console.error("Fetching URLs from ethereum-lists GitHub...");
+    let urlsFound = 0;
+
+    for (let i = 0; i < tokens.length; i += CONCURRENT) {
+        const batch = tokens.slice(i, i + CONCURRENT);
+        await Promise.all(
+            batch.map(async (t) => {
+                const r = await fetch(`${ETHEREUM_LISTS}/${t.address}.json`);
+                if (r.status === 404) return;
+                if (!r.ok) {
+                    throw new Error(
+                        `ethereum-lists HTTP ${r.status} for ${t.address}`,
+                    );
+                }
+                const data = await r.json();
+                const website = (data.website || "").trim();
+                if (website && website !== "https://") {
+                    enriched.get(t.address).url = website;
+                    urlsFound++;
+                }
+            }),
+        );
+        if (i % 100 === 0) {
+            console.error(
+                `  GitHub: ${Math.min(i + CONCURRENT, tokens.length)}/${tokens.length}, ${urlsFound} URLs`,
+            );
+        }
+        await sleep(200);
+    }
+    console.error(`Found ${urlsFound} URLs in ethereum-lists`);
+
+    // --- Output, in the layout prettier gives it ---
+    const output = {};
+    for (const [addr, e] of enriched) {
+        output[addr] = { name: e.name, url: e.url };
+    }
+    fs.writeFileSync(OUTPUT, JSON.stringify(output, null, 4) + "\n");
+    console.error(`Done! ${tokens.length} names, ${urlsFound} URLs.`);
+}
+
+main().catch((err) => {
+    console.error(`enrich-tokens: ${err.message}`);
+    process.exit(1);
+});