fix: Home's Send and Receive clear the selected token (closes #753)

Three routes reach Home with a token still selected. Send used that token
whatever its dropdown showed, and Receive warned about it. Both now clear it
when they open, and Send's dropdown starts on ETH.

Model: opus-5-5

src/popup/views/home.js

@@ -510,11 +510,15 @@ function init(ctx) {
             showFlash("Cannot send \u2014 zero balance.");
             return;
         }
+        // Send uses a selected token ahead of its dropdown, and AddressToken
+        // can leave one selected on the way here.
+        state.selectedToken = null;
         $("send-to").value = "";
         $("send-amount").value = "";
         $("send-token-dropdown").classList.remove("hidden");
         $("send-token-static").classList.add("hidden");
         renderSendTokenSelect(addr);
+        $("send-token").value = "ETH";
         updateSendBalance();
         resetSendValidation();
         pushCurrentView();
@@ -526,6 +530,9 @@ function init(ctx) {
             showFlash("No active address selected.");
             return;
         }
+        // Receive warns about a selected token, and AddressToken can leave one
+        // selected on the way here.
+        state.selectedToken = null;
         ctx.showReceive();
     });
 }