feat: password-gated recovery phrase display for HD wallets (closes #161)

A user who created a wallet in AutistMask and did not write the phrase
down had no way to retrieve it. Adds a "Show recovery phrase" action on
the wallet row in Settings, next to the per-wallet actions that already
live there, mirroring the per-address private key export in structure,
password gate and warning treatment.

The screen displays the secret that owns every address in the wallet, so:

  - Only HD wallets are offered it. walletHasRecoveryPhrase() is an
    allowlist on type "hd", so the key and xprv types — which have no
    phrase at all — are excluded, as is any type added later.
  - Nothing is decrypted and nothing enters the page until
    decryptWithPassword accepts the password. A wrong password produces a
    full-sentence error and leaves the value node empty.
  - Leaving the screen wipes it by any route, not just "Back": views that
    hold a secret register a cleanup with showView() via onViewLeave(),
    which also covers the settings gear.
  - The phrase is never assigned to state, so it cannot be persisted, and
    the view is not in RESTORABLE_VIEWS — reopening the popup lands on
    Home. That set moves to src/popup/restorableViews.js so the exclusion
    can be asserted directly; the popup entry point cannot be required
    outside a browser.
  - The phrase cannot reach the logger: the view does not import
    src/shared/log.js, and the failed-decrypt path reports a fixed
    sentence rather than the caught error.

Tests: unit coverage for the type gate, the RESTORABLE_VIEWS exclusion
and the absence of any logger path; the DOM behaviour is driven against
the real popup in the e2e suite, which is where this repo tests views.

src/popup/views/helpers.js

@@ -31,8 +31,20 @@ const VIEWS = [
     "approve-tx",
     "approve-sign",
     "export-privkey",
+    "show-phrase",
 ];
 
+// Cleanup callbacks for views that hold a secret in the DOM. The view
+// registers one for itself and showView() runs it whenever that view is
+// navigated away from, so the secret is wiped no matter which control
+// caused the navigation — "Back", the settings gear, or a jump from
+// anywhere else. A per-button clear would only cover the one path.
+const viewLeaveHandlers = new Map();
+
+function onViewLeave(name, fn) {
+    viewLeaveHandlers.set(name, fn);
+}
+
 function $(id) {
     return document.getElementById(id);
 }
@@ -50,6 +62,11 @@ function hideError(id) {
 }
 
 function showView(name) {
+    const leaving = state.currentView;
+    if (leaving && leaving !== name) {
+        const onLeave = viewLeaveHandlers.get(leaving);
+        if (onLeave) onLeave();
+    }
     for (const v of VIEWS) {
         const el = document.getElementById(`view-${v}`);
         if (el) {
@@ -431,10 +448,12 @@ function flashCopyFeedback(el) {
 }
 
 module.exports = {
+    VIEWS,
     $,
     showError,
     hideError,
     showView,
+    onViewLeave,
     updateDebugBanner,
     setRenderMain,
     pushCurrentView,

src/popup/views/settings.js

@@ -14,6 +14,8 @@ const { NETWORKS, SUPPORTED_CHAIN_IDS } = require("../../shared/networks");
 const { onChainSwitch } = require("../../shared/chainSwitch");
 const { log, debugFetch, setRuntimeDebug } = require("../../shared/log");
 const deleteWallet = require("./deleteWallet");
+const showPhrase = require("./showPhrase");
+const { walletHasRecoveryPhrase } = require("../../shared/wallet");
 const {
     BUILD_VERSION,
     BUILD_LICENSE,
@@ -99,7 +101,14 @@ function renderWalletListSettings() {
         const name = escapeHtml(wallet.name || "Wallet " + (idx + 1));
         html += `<div class="flex justify-between items-center text-xs py-1 border-b border-border-light">`;
         html += `<span class="settings-wallet-name cursor-pointer underline decoration-dashed" data-idx="${idx}">${name}</span>`;
+        html += `<span class="flex items-center gap-1 flex-shrink-0">`;
+        // Key and xprv wallets have no recovery phrase, so they are never
+        // offered the action at all.
+        if (walletHasRecoveryPhrase(wallet)) {
+            html += `<button class="btn-show-phrase border border-border px-1 hover:bg-fg hover:text-bg cursor-pointer" data-idx="${idx}" title="Show recovery phrase">[recovery phrase]</button>`;
+        }
         html += `<button class="btn-delete-wallet border border-border px-1 hover:bg-fg hover:text-bg cursor-pointer" data-idx="${idx}">[x]</button>`;
+        html += `</span>`;
         html += `</div>`;
     });
     container.innerHTML = html;
@@ -111,6 +120,14 @@ function renderWalletListSettings() {
         });
     });
 
+    container.querySelectorAll(".btn-show-phrase").forEach((btn) => {
+        btn.addEventListener("click", () => {
+            const idx = parseInt(btn.dataset.idx, 10);
+            pushCurrentView();
+            showPhrase.show(idx);
+        });
+    });
+
     // Inline rename on click
     container.querySelectorAll(".settings-wallet-name").forEach((span) => {
         span.addEventListener("click", () => {
@@ -191,6 +208,7 @@ function renderSiteLists() {
 
 function init(ctx) {
     deleteWallet.init(ctx);
+    showPhrase.init();
 
     $("btn-save-rpc").addEventListener("click", async () => {
         const url = $("settings-rpc").value.trim();

src/popup/views/showPhrase.js

@@ -0,0 +1,122 @@
+// Recovery phrase display for HD wallets.
+//
+// The phrase is the secret that owns every address in the wallet, so it is
+// handled under four rules:
+//
+//   1. Only an HD wallet reaches this screen (walletHasRecoveryPhrase).
+//   2. Nothing is decrypted, and nothing is written into the DOM, until
+//      decryptWithPassword has accepted the password.
+//   3. Leaving the screen by any path wipes it, via the onViewLeave hook.
+//   4. The phrase never reaches the logger. This module deliberately does
+//      not import src/shared/log.js, and the failed-decrypt path reports a
+//      fixed sentence rather than the caught error.
+//
+// The phrase is also never assigned to `state`, so it cannot be persisted
+// to extension storage, and "show-phrase" is excluded from RESTORABLE_VIEWS
+// so the popup can never reopen onto it.
+
+const {
+    $,
+    showView,
+    showFlash,
+    flashCopyFeedback,
+    goBack,
+    onViewLeave,
+} = require("./helpers");
+const { state } = require("../../shared/state");
+const { decryptWithPassword } = require("../../shared/vault");
+const { walletHasRecoveryPhrase } = require("../../shared/wallet");
+
+const VIEW = "show-phrase";
+
+let walletIndex = null;
+
+function fail(message) {
+    $("show-phrase-flash").textContent = message;
+    $("show-phrase-flash").style.visibility = "visible";
+}
+
+// Wipe every trace of the phrase and drop the wallet selection. Safe to
+// call when nothing was ever revealed, and safe to call twice.
+function clear() {
+    walletIndex = null;
+    $("show-phrase-value").textContent = "";
+    $("show-phrase-password").value = "";
+    $("show-phrase-result").classList.add("hidden");
+    $("show-phrase-password-section").classList.remove("hidden");
+    $("show-phrase-flash").textContent = "";
+    $("show-phrase-flash").style.visibility = "hidden";
+}
+
+function show(walletIdx) {
+    const wallet = state.wallets[walletIdx];
+    if (!walletHasRecoveryPhrase(wallet)) {
+        showFlash("This wallet does not have a recovery phrase.");
+        return;
+    }
+    clear();
+    walletIndex = walletIdx;
+    $("show-phrase-wallet-name").textContent =
+        wallet.name || "Wallet " + (walletIdx + 1);
+    showView(VIEW);
+}
+
+async function reveal() {
+    const password = $("show-phrase-password").value;
+    if (!password) {
+        fail("Please enter your password.");
+        return;
+    }
+    if (walletIndex === null) {
+        fail("No wallet is selected.");
+        return;
+    }
+    const wallet = state.wallets[walletIndex];
+    if (!walletHasRecoveryPhrase(wallet)) {
+        fail("This wallet does not have a recovery phrase.");
+        return;
+    }
+
+    const btn = $("btn-show-phrase-reveal");
+    btn.disabled = true;
+    btn.classList.add("text-muted");
+    try {
+        const phrase = await decryptWithPassword(
+            wallet.encryptedSecret,
+            password,
+        );
+        $("show-phrase-password").value = "";
+        $("show-phrase-password-section").classList.add("hidden");
+        $("show-phrase-value").textContent = phrase;
+        $("show-phrase-result").classList.remove("hidden");
+        $("show-phrase-flash").textContent = "";
+        $("show-phrase-flash").style.visibility = "hidden";
+    } catch {
+        // Deliberately not the caught error: the message is fixed so that
+        // nothing derived from the ciphertext or the attempt can surface.
+        fail("That password is not correct. Please try again.");
+    } finally {
+        btn.disabled = false;
+        btn.classList.remove("text-muted");
+    }
+}
+
+function init() {
+    onViewLeave(VIEW, clear);
+
+    $("btn-show-phrase-back").addEventListener("click", () => {
+        goBack();
+    });
+
+    $("btn-show-phrase-reveal").addEventListener("click", reveal);
+
+    $("show-phrase-value").addEventListener("click", () => {
+        const phrase = $("show-phrase-value").textContent;
+        if (!phrase) return;
+        navigator.clipboard.writeText(phrase);
+        showFlash("Copied!");
+        flashCopyFeedback($("show-phrase-value"));
+    });
+}
+
+module.exports = { init, show };