Add spinner feedback to Sign in with Nostr button while loading pubkey

src/index.html

@@ -453,6 +453,28 @@
       border-radius: 8px;
       padding: 7px 10px;
       box-shadow: 0 1px 2px rgba(15, 23, 42, .04);
+      transition: opacity .15s;
+    }
+
+    .pill:disabled {
+      opacity: .7;
+      cursor: wait;
+    }
+
+    .pill .spinner {
+      display: inline-block;
+      width: 14px;
+      height: 14px;
+      border: 2px solid var(--line);
+      border-top-color: var(--accent);
+      border-radius: 50%;
+      margin-right: 6px;
+      animation: spin .55s linear infinite;
+      vertical-align: -2px;
+    }
+
+    @keyframes spin {
+      to { transform: rotate(360deg); }
     }
 
     .previewShell {
@@ -4404,13 +4426,22 @@
     }
 
     async function nostrLogin() {
-      const pubkey = await getNostrPublicKey();
-      if (!pubkey) {
-        alert('No Nostr extension found. Install Alby, nos2x, or another NIP-07 extension.');
-        return;
+      const loginBtn = $('nostrLoginBtn');
+      const orig = loginBtn.innerHTML;
+      loginBtn.disabled = true;
+      loginBtn.innerHTML = '<span class="spinner"></span>Sign in with Nostr';
+      try {
+        const pubkey = await getNostrPublicKey();
+        if (!pubkey) {
+          alert('No Nostr extension found. Install Alby, nos2x, or another NIP-07 extension.');
+          return;
+        }
+        state.community.myPubkey = pubkey;
+        await loadCommunityIdentity();
+      } finally {
+        loginBtn.disabled = false;
+        loginBtn.innerHTML = orig;
       }
-      state.community.myPubkey = pubkey;
-      await loadCommunityIdentity();
     }
 
     async function loadMyDesigns() {