feat(chat): implement initial chatbot UI and functionality

This commit introduces the foundational user-facing chatbot interface.

- Adds a new `ChatbotPage` component with a complete UI for displaying messages, user input, and a simulated bot response.
- Implements a "typing" indicator for a better user experience.
- Integrates `react-router-dom` to handle application routing, directing the root path to the new chatbot and moving the admin login to `/admin`.
- Adds `react-icons` as a new dependency for UI elements.
- Extends Tailwind CSS theme with new colors and adds custom CSS for the typing animation.

adventure-rental-app/tailwind.config.js

@@ -12,6 +12,9 @@ export default {
         'brand-light': '#F5F5DC',
         'brand-gray': '#A9A9A9',
         'brand-orange': '#D97706', // Adventure Orange
+        'chat-header': '#003C5A',
+        'chat-bg': '#0084A8',
+        'chat-input-bg': '#0A192F',
       },
       fontFamily: {
         sans: ['Poppins', 'sans-serif'],