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.

whatsapp-router/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 (if it has an HTTP server for internal checks, though not strictly necessary for a router)
+EXPOSE 3001
+
+# Define the command to run the app
+CMD [ "node", "router.js" ]

whatsapp-router/package.json

@@ -0,0 +1,12 @@
+{
+  "name": "whatsapp-router",
+  "version": "1.0.0",
+  "description": "WhatsApp Router for OpenWA and LLM Agent",
+  "main": "router.js",
+  "scripts": {
+    "start": "node router.js"
+  },
+  "dependencies": {
+    "express": "^4.17.1"
+  }
+}

whatsapp-router/router.js

@@ -0,0 +1,16 @@
+const express = require('express');
+const app = express();
+const PORT = process.env.PORT || 3001;
+
+app.use(express.json());
+
+app.post('/webhook', (req, res) => {
+  console.log('Received webhook event:', req.body);
+  // Logic to process OpenWA event and interact with LLM agent will go here
+  res.status(200).send('Event received');
+});
+
+app.listen(PORT, () => {
+  console.log(`WhatsApp Router listening on port ${PORT}`);
+  console.log('Webhook endpoint available at /webhook');
+});