feat(chat): Integrate chatbot API for dynamic responses

This commit replaces the static, simulated chat functionality with a live integration to a chatbot backend API.

The chat page now sends user messages to a webhook endpoint using the `fetch` API. It implements session management by generating and storing a `sessionId` in `localStorage` to maintain conversation context between requests.

Key changes:
- Implement `async` `sendMessage` function to post to the chatbot API.
- Add session ID generation and persistence.
- Dynamically render text and image responses from the API.
- Remove hardcoded example messages from the HTML.
- Update the virtual assistant's name to "Maya".
- Fix navigation links from the dashboard to the chat page.

chat-page/index.html

@@ -27,9 +27,9 @@
         <!-- Header dengan avatar dan nama pengguna -->
         <header class="chat-header">
 <div class="user-info">
-    <div class="avatar">J</div>
+    <div class="avatar">M</div>
     <div class="user-details">
-        <h2>John Doe</h2>
+        <h2>Maya</h2>
         <span class="user-role">Virtual Assistant - Bake Shop</span>
     </div>
 </div>
@@ -37,21 +37,6 @@
         
         <!-- Area chat utama -->
         <div class="chat-area">
-            <!-- Contoh pesan masuk -->
-            <div class="message received">
-                <div class="message-content">
-                    Hai, ada kabar terbaru?
-                </div>
-                <div class="message-time">10:00</div>
-            </div>
-            
-            <!-- Contoh pesan keluar -->
-            <div class="message sent">
-                <div class="message-content">
-                    Iya, proyek baru sudah selesai!
-                </div>
-                <div class="message-time">10:01</div>
-            </div>
         </div>
         
         <!-- Input area with WhatsApp-like design -->