feat: Initial Docker Compose setup for conversation layer

Adds a docker-compose.yml to manage the OpenWA, Chat UI, and WhatsApp Router services.

Includes:
- Dockerfile and basic Node.js skeleton for Chat UI.
- Dockerfile and basic Node.js skeleton for WhatsApp Router.
- docker-compose.yml defining the three services, including:
    - Placeholder for OpenWA image (you must configure this).
    - Build contexts for UI and router.
    - Port mappings.
    - Environment variable examples.
    - Volume for OpenWA session persistence.
- Updated README.md with detailed setup, configuration, and usage instructions.

chat-ui/Dockerfile

@@ -0,0 +1,20 @@
+# Use an official Node.js runtime as a parent image
+FROM node:18-slim
+
+# Set the working directory in the container
+WORKDIR /usr/src/app
+
+# Copy package.json and package-lock.json (or yarn.lock)
+COPY package*.json ./
+
+# Install application dependencies
+RUN npm install
+
+# Bundle app source
+COPY . .
+
+# Expose the port the app runs on
+EXPOSE 3000
+
+# Define the command to run the app
+CMD [ "node", "server.js" ]

chat-ui/package.json

@@ -0,0 +1,12 @@
+{
+  "name": "chat-ui",
+  "version": "1.0.0",
+  "description": "Chat UI for LLM Agent",
+  "main": "server.js",
+  "scripts": {
+    "start": "node server.js"
+  },
+  "dependencies": {
+    "express": "^4.17.1"
+  }
+}

chat-ui/server.js

@@ -0,0 +1,11 @@
+const express = require('express');
+const app = express();
+const PORT = process.env.PORT || 3000;
+
+app.get('/', (req, res) => {
+  res.send('Chat UI is running!');
+});
+
+app.listen(PORT, () => {
+  console.log(`Chat UI listening on port ${PORT}`);
+});