chore: remove dead exports and share copied view helpers (closes #168)

AddressDetail and AddressToken defined their own isoDate() and
timeAgo(), hiding the shared pair in helpers.js, so a fix there would
not have reached them. The copies were identical and are deleted;
blockieHtml() and tokenLabel(), each defined twice, move to helpers.js.
A new test shows the history rows and the transaction detail view
write the time with the shared pair.

Deleted as never called: explorerLink(), ETHEREUM_SEPOLIA_CHAIN_ID,
getWalletValue() and getTotalValue() with their tests. Home's "Total:"
is the active address's total, as README.md already says.
addressColor() and etherscanAddressUrl() are no longer exported.

Model: opus-5-5

src/popup/views/addressToken.js

@@ -17,6 +17,8 @@ const {
     attachCopyHandlers,
     goBack,
     pushCurrentView,
+    isoDate,
+    timeAgo,
 } = require("./helpers");
 const { state, saveState, currentNetwork } = require("../../shared/state");
 const { TOKEN_BY_ADDRESS, resolveSymbol } = require("../../shared/tokenList");
@@ -37,62 +39,6 @@ const { walletDefect } = require("../../shared/walletDefects");
 
 let ctx;
 
-function isoDate(timestamp) {
-    const d = new Date(timestamp * 1000);
-    const pad = (n) => String(n).padStart(2, "0");
-    if (state.utcTimestamps) {
-        return (
-            d.getUTCFullYear() +
-            "-" +
-            pad(d.getUTCMonth() + 1) +
-            "-" +
-            pad(d.getUTCDate()) +
-            "T" +
-            pad(d.getUTCHours()) +
-            ":" +
-            pad(d.getUTCMinutes()) +
-            ":" +
-            pad(d.getUTCSeconds()) +
-            "Z"
-        );
-    }
-    const offsetMin = -d.getTimezoneOffset();
-    const sign = offsetMin >= 0 ? "+" : "-";
-    const absOff = Math.abs(offsetMin);
-    const tzStr = sign + pad(Math.floor(absOff / 60)) + ":" + pad(absOff % 60);
-    return (
-        d.getFullYear() +
-        "-" +
-        pad(d.getMonth() + 1) +
-        "-" +
-        pad(d.getDate()) +
-        "T" +
-        pad(d.getHours()) +
-        ":" +
-        pad(d.getMinutes()) +
-        ":" +
-        pad(d.getSeconds()) +
-        tzStr
-    );
-}
-
-function timeAgo(timestamp) {
-    const seconds = Math.floor(Date.now() / 1000 - timestamp);
-    if (seconds < 60) return seconds + " seconds ago";
-    const minutes = Math.floor(seconds / 60);
-    if (minutes < 60)
-        return minutes + " minute" + (minutes !== 1 ? "s" : "") + " ago";
-    const hours = Math.floor(minutes / 60);
-    if (hours < 24) return hours + " hour" + (hours !== 1 ? "s" : "") + " ago";
-    const days = Math.floor(hours / 24);
-    if (days < 30) return days + " day" + (days !== 1 ? "s" : "") + " ago";
-    const months = Math.floor(days / 30);
-    if (months < 12)
-        return months + " month" + (months !== 1 ? "s" : "") + " ago";
-    const years = Math.floor(days / 365);
-    return years + " year" + (years !== 1 ? "s" : "") + " ago";
-}
-
 let loadedTxs = [];
 let ensNameMap = new Map();
 let currentSymbol = null;