Flush pending approval popups on address switch

When switching addresses, reject and close any open approval popup
windows so their promises don't hang forever. Without this, stale
pending approvals from automatic dapp reconnection attempts block
future connection requests.

src/background/index.js

@@ -336,6 +336,18 @@ async function broadcastAccountsChanged() {
     for (const key of Object.keys(connectedSites)) {
         delete connectedSites[key];
     }
+    // Reject and close any pending approval popups so they don't hang
+    for (const [id, approval] of Object.entries(pendingApprovals)) {
+        approval.resolve({ approved: false, remember: false });
+        if (approval.windowId) {
+            windowsApi.remove(approval.windowId, () => {
+                if (runtime.lastError) {
+                    // window already closed
+                }
+            });
+        }
+        delete pendingApprovals[id];
+    }
     const s = await getState();
     const activeAddress = await getActiveAddress();
     const allowed = activeAddress ? s.allowedSites[activeAddress] || [] : [];