Add token management to Settings

- Tracked Tokens well in settings with [x] remove buttons
- New settings-addtoken view with:
  - Top-10 quick-pick buttons (tracked ones dimmed+disabled)
  - Top-100 dropdown showing "Token Name (SYMBOL)", tracked disabled
  - Manual contract address entry with RPC lookup
- View comment in helpers.js about keeping README in sync

src/popup/views/settingsAddToken.js

@@ -0,0 +1,159 @@
+const { $, showView, showFlash } = require("./helpers");
+const { getTopTokens } = require("../../shared/tokenList");
+const { state, saveState } = require("../../shared/state");
+const { lookupTokenInfo } = require("../../shared/balances");
+const { isScamAddress } = require("../../shared/scamlist");
+const { log } = require("../../shared/log");
+
+let ctx;
+
+function isTracked(address) {
+    const lower = address.toLowerCase();
+    return state.trackedTokens.some((t) => t.address.toLowerCase() === lower);
+}
+
+function tokenLabel(t) {
+    return t.name ? t.name + " (" + t.symbol + ")" : t.symbol;
+}
+
+function renderTop10() {
+    const el = $("settings-addtoken-top10");
+    el.innerHTML = getTopTokens(10)
+        .map((t) => {
+            const tracked = isTracked(t.address);
+            const cls = tracked
+                ? "border border-border px-1 text-xs opacity-40 cursor-default"
+                : "border border-border px-1 hover:bg-fg hover:text-bg cursor-pointer text-xs";
+            return (
+                `<button class="settings-addtoken-quick ${cls}"` +
+                ` data-address="${t.address}"` +
+                ` data-symbol="${t.symbol}"` +
+                ` data-decimals="${t.decimals}"` +
+                ` data-name="${(t.name || "").replace(/"/g, "&quot;")}"` +
+                `${tracked ? " disabled" : ""}>${t.symbol}</button>`
+            );
+        })
+        .join("");
+    el.querySelectorAll(".settings-addtoken-quick:not([disabled])").forEach(
+        (btn) => {
+            btn.addEventListener("click", async () => {
+                const token = {
+                    address: btn.dataset.address,
+                    symbol: btn.dataset.symbol,
+                    decimals: parseInt(btn.dataset.decimals, 10),
+                    name: btn.dataset.name || btn.dataset.symbol,
+                };
+                state.trackedTokens.push(token);
+                await saveState();
+                showFlash("Added " + token.symbol);
+                renderTop10();
+                renderDropdown();
+                ctx.doRefreshAndRender();
+            });
+        },
+    );
+}
+
+function renderDropdown() {
+    const sel = $("settings-addtoken-select");
+    const tokens = getTopTokens(100);
+    let html = '<option value="">-- select --</option>';
+    for (const t of tokens) {
+        const tracked = isTracked(t.address);
+        const label = tokenLabel(t) + (tracked ? " (tracked)" : "");
+        html +=
+            `<option value="${t.address}"` +
+            ` data-symbol="${t.symbol}"` +
+            ` data-decimals="${t.decimals}"` +
+            ` data-name="${(t.name || "").replace(/"/g, "&quot;")}"` +
+            `${tracked ? " disabled" : ""}>${label}</option>`;
+    }
+    sel.innerHTML = html;
+}
+
+function show() {
+    $("settings-addtoken-address").value = "";
+    $("settings-addtoken-info").classList.add("hidden");
+    renderTop10();
+    renderDropdown();
+    showView("settings-addtoken");
+}
+
+function init(_ctx) {
+    ctx = _ctx;
+
+    $("btn-settings-addtoken-back").addEventListener("click", () => {
+        ctx.showSettingsView();
+    });
+
+    $("btn-settings-addtoken-select").addEventListener("click", async () => {
+        const sel = $("settings-addtoken-select");
+        const opt = sel.options[sel.selectedIndex];
+        if (!opt || !opt.value) {
+            showFlash("Please select a token.");
+            return;
+        }
+        if (isTracked(opt.value)) {
+            showFlash("Already tracked.");
+            return;
+        }
+        const token = {
+            address: opt.value,
+            symbol: opt.dataset.symbol,
+            decimals: parseInt(opt.dataset.decimals, 10),
+            name: opt.dataset.name || opt.dataset.symbol,
+        };
+        state.trackedTokens.push(token);
+        await saveState();
+        showFlash("Added " + token.symbol);
+        renderTop10();
+        renderDropdown();
+        ctx.doRefreshAndRender();
+    });
+
+    $("btn-settings-addtoken-manual").addEventListener("click", async () => {
+        const addr = $("settings-addtoken-address").value.trim();
+        if (!addr || !addr.startsWith("0x")) {
+            showFlash(
+                "Please enter a valid contract address starting with 0x.",
+            );
+            return;
+        }
+        if (isTracked(addr)) {
+            showFlash("Already tracked.");
+            return;
+        }
+        if (isScamAddress(addr)) {
+            showFlash("This address is on a known scam/fraud list.");
+            return;
+        }
+        const infoEl = $("settings-addtoken-info");
+        infoEl.textContent = "Looking up token...";
+        infoEl.classList.remove("hidden");
+        log.debugf("Looking up token contract", addr);
+        try {
+            const info = await lookupTokenInfo(addr, state.rpcUrl);
+            log.infof("Adding token", info.symbol, addr);
+            state.trackedTokens.push({
+                address: addr,
+                symbol: info.symbol,
+                decimals: info.decimals,
+                name: info.name,
+            });
+            await saveState();
+            showFlash("Added " + info.symbol);
+            $("settings-addtoken-address").value = "";
+            infoEl.classList.add("hidden");
+            renderTop10();
+            renderDropdown();
+            ctx.doRefreshAndRender();
+        } catch (e) {
+            const detail = e.shortMessage || e.message || String(e);
+            log.errorf("Token lookup failed for", addr, detail);
+            showFlash(detail);
+            infoEl.classList.add("hidden");
+        }
+    });
+}
+
+module.exports = { init, show };