fix: Blockscout and Etherscan lookups are off until the user turns them on (closes #668)

Out of the box the wallet sent the user's addresses to Blockscout and each recipient's address to Etherscan. Two settings, "Use Blockscout" and "Check recipients on Etherscan", now gate every request that sends the user's data to those services. Both start off and are offered unticked on Welcome and in Settings. Each request reads its setting from storage before it asks. An answer that lands after the setting went off is dropped. While a setting is off, the screens that rely on it say so. ENS lookups ask only the RPC endpoint, so a name resolved off-chain does not resolve.

RULES.md's External Communication item is now out of date. Its new wording will be proposed on #211 once this lands.

Model: opus-5-5 (implementation, summary); fable-5-1 (prose)

src/popup/index.js

@@ -11,7 +11,7 @@ const {
 const { StateUnusableError } = require("../shared/stateSchema");
 const { log, setRuntimeDebug } = require("../shared/log");
 const { refreshPrices } = require("../shared/prices");
-const { refreshBalances } = require("../shared/balances");
+const { refreshBalances, dropUntrackedTokens } = require("../shared/balances");
 const { clearPopupCaches } = require("../shared/chainSwitch");
 const {
     $,
@@ -71,21 +71,28 @@ let refreshInFlight = false;
 // the recovery screen: there is no profile left to refresh.
 let refreshTimer = null;
 
+// The refresh first takes the stored network, "Use Blockscout" and "Check
+// recipients on Etherscan" (followStoredSettings() below). So the screens it
+// draws reflect any change saved elsewhere.
+//
 // The refresh writes into a copy of the wallets. Inside the save, under the
 // lock, its results are copied onto the address records in `state` only if the
 // network it ran on is still the active one, on this page and in the stored
 // record; the background's switch, after the user approves a site's request,
-// reaches this page only after the stored record (followNetworkSwitch() below).
+// reaches this page only after the stored record (followStoredSettings()).
 // A switch while the refresh ran cleared every address's balances
 // (applyChainSwitchFields() in src/shared/chainSwitchFields.js), and the
 // previous network's must not come back over them
 // (https://git.eeqj.de/sneak/AutistMask/issues/577). A dropped refresh is not
 // recorded as done. Results are copied by address, so an address added or
-// removed meanwhile is left as it is.
+// removed meanwhile is left as it is. Blockscout may have answered before the
+// user turned "Use Blockscout" off. So the save drops every token the user has
+// not tracked if the stored setting is off by then.
 async function doRefreshAndRender() {
     if (refreshInFlight) return;
     refreshInFlight = true;
     try {
+        await followStoredSettings();
         const networkId = state.networkId;
         const wallets = structuredClone(state.wallets);
         await Promise.all([
@@ -117,6 +124,9 @@ async function doRefreshAndRender() {
                     }
                 }
             }
+            if (!stored.useBlockscout) {
+                dropUntrackedTokens(state.wallets, stored.trackedTokens);
+            }
             state.lastBalanceRefresh = Date.now();
             return true;
         });
@@ -228,17 +238,36 @@ function fallbackView() {
 // src/shared/chainSwitch.js), so a record naming a network other than this
 // page's always holds a switch saved elsewhere, and a switch the user picks
 // here while this waits for the lock is made after it.
-async function followNetworkSwitch() {
-    let switched = false;
+//
+// Another page may change "Use Blockscout" or "Check recipients on Etherscan".
+// This page takes either change the same way and draws its screens again. This
+// page's own changes to the two settings are made under the lock too
+// (views/settings.js, views/welcome.js).
+async function followStoredSettings() {
+    let changed = false;
     // A failed save is reported by saveState() itself: see onSaveFailure().
     await saveState((stored) => {
-        if (stored.networkId === state.networkId) return false;
-        settings.cutViewStack();
-        takeStoredNetwork(stored);
-        clearPopupCaches();
-        switched = true;
+        if (stored.networkId !== state.networkId) {
+            settings.cutViewStack();
+            takeStoredNetwork(stored);
+            clearPopupCaches();
+            changed = true;
+        }
+        if (stored.useBlockscout !== state.useBlockscout) {
+            settings.setUseBlockscout(stored.useBlockscout);
+            changed = true;
+        }
+        if (
+            stored.checkRecipientsOnEtherscan !==
+            state.checkRecipientsOnEtherscan
+        ) {
+            state.checkRecipientsOnEtherscan =
+                stored.checkRecipientsOnEtherscan;
+            changed = true;
+        }
+        if (!changed) return false;
     }).catch(() => {});
-    if (switched) settings.showNewNetwork();
+    if (changed) settings.showNewSettings();
 }
 
 // The background opens the approval window as wide as the page, but the
@@ -385,19 +414,27 @@ async function init() {
     settingsAddToken.init(ctx);
     deleteAddress.init(ctx);
 
-    // Only a record naming a network other than this page's is followed: the
-    // one this page's own switch in Settings saves names the network it
-    // already has, and a record naming none is no switch.
+    // This page follows a record only when its network, "Use Blockscout" or
+    // "Check recipients on Etherscan" differs from this page's. A record
+    // written by this page's own save matches this page. A record naming no
+    // network is no switch.
     onStorageChanged((changes) => {
         const written = changes.autistmask && changes.autistmask.newValue;
         if (!written || !written.networkId) return;
-        if (written.networkId !== state.networkId) followNetworkSwitch();
+        if (
+            written.networkId !== state.networkId ||
+            written.useBlockscout !== state.useBlockscout ||
+            written.checkRecipientsOnEtherscan !==
+                state.checkRecipientsOnEtherscan
+        ) {
+            followStoredSettings();
+        }
     });
-    // A switch saved since loadState() above, before there was a listener.
-    followNetworkSwitch();
+    // A change saved since loadState() above, before there was a listener.
+    followStoredSettings();
 
     if (!state.hasWallet) {
-        showView("welcome");
+        welcome.show();
     } else {
         renderWalletList();
         restoreView();