Hide zap button when inappropriate

* Current user has No Nostr pubkey connected
* Creator can't accept zaps
* Creator is current user (self-zap)

tests/helpers/mock-nostr.js

@@ -9,7 +9,12 @@ export class MockNostrAuthService extends Service {
   @tracked connectUri = null;
 
   get isConnected() {
-    return false;
+    return (
+      !!this.pubkey &&
+      (this.signerType === 'extension'
+        ? typeof window !== 'undefined' && typeof window.nostr !== 'undefined'
+        : true)
+    );
   }
 
   get isMobile() {

tests/integration/components/photo-gallery-test.gjs

@@ -480,7 +480,8 @@ module('Integration | Component | photo-gallery', function (hooks) {
   });
 
   test('it shows Zap this photo in the dropdown', async function (assert) {
-    this.nostrAuth.pubkey = USER_A;
+    this.nostrAuth.pubkey = USER_B;
+    this.nostrAuth.signerType = 'connect';
     this.selectedPhoto = this.photos[0];
 
     await render(
@@ -508,7 +509,8 @@ module('Integration | Component | photo-gallery', function (hooks) {
   });
 
   test('it opens zap modal when Zap this photo is clicked', async function (assert) {
-    this.nostrAuth.pubkey = USER_A;
+    this.nostrAuth.pubkey = USER_B;
+    this.nostrAuth.signerType = 'connect';
     this.selectedPhoto = this.photos[0];
 
     await render(