Fix feed2.html: add missing walletGetBalance and walletGetMints imports

feed2.html was missing walletGetBalance and walletGetMints in both the
init-ndk.mjs import and the initPostCards call. Without these, the zap
rail selector and capability badges couldn't function — handleZapClick
couldn't resolve zap capabilities or show the rail toggle.

www/feed2.html

@@ -155,6 +155,8 @@
       walletPayInvoice,
       walletSendNutzap,
       walletFetchMintList,
+      walletGetBalance,
+      walletGetMints,
       getRelayData,
       getUserSettings,
       patchUserSettings,
@@ -331,6 +333,8 @@ import { initPostCards } from './js/post-interactions2.mjs';
       walletPayInvoice,
       walletSendNutzap,
       walletFetchMintList,
+      walletGetBalance,
+      walletGetMints,
       getRelayData,
       getUserSettings,
       patchUserSettings,

www/js/version.json

@@ -1,5 +1,5 @@
 {
-  "VERSION": "v0.7.30",
-  "VERSION_NUMBER": "0.7.30",
-  "BUILD_DATE": "2026-06-26T00:48:38.325Z"
+  "VERSION": "v0.7.31",
+  "VERSION_NUMBER": "0.7.31",
+  "BUILD_DATE": "2026-06-26T00:55:02.798Z"
 }