feat: Include chat public key in conversation data and enhance chat page layout for full width and dynamic height.

src/app/chat/chat.css

@@ -1,7 +1,12 @@
 /* Chat Page Styles */
 
 .chat-page {
-  height: calc(100vh - 60px);
+  height: 100vh;
+  /* Use dynamic viewport height for mobile browsers */
+  height: 100dvh;
+  max-height: 100dvh;
+  display: flex;
+  flex-direction: column;
 }
 
 .chat-container {

src/app/chat/page.tsx

@@ -9,7 +9,12 @@ import './chat.css';
 
 interface Conversation {
   id: string;
-  participant2: { handle: string; displayName: string; avatarUrl: string | null; chatPublicKey: string | null; };
+  participant2: {
+    handle: string;
+    displayName: string;
+    avatarUrl: string | null;
+    chatPublicKey: string | null;
+  };
   lastMessageAt: string;
   lastMessagePreview: string;
   unreadCount: number;