feat: Refactor LLM router and integrate health check endpoint

- Simplified LLM call logic in llm_router.py, removing tool adapter complexity and enhancing error handling.
- Added health check endpoint to main.py for system status verification.
- Cleaned up router.py by removing unused imports and commented-out code, streamlining the structure.
- Updated docker-compose.yml to unify services under a single Lyra container, enhancing deployment simplicity.
- Created Dockerfile for unified container setup, including both Relay and Cortex services.
- Added QUICKSTART.md for improved onboarding and usage instructions.
- Implemented start.sh script to manage service startup and health checks.

start.sh

@@ -0,0 +1,34 @@
+#!/bin/bash
+# Unified startup script for Lyra (Relay + Cortex)
+
+set -e
+
+echo "🚀 Starting Lyra unified container..."
+
+# Start Cortex (Python/FastAPI) in the background
+echo "📡 Starting Cortex on port 7081..."
+cd /app/cortex
+uvicorn main:app --host 0.0.0.0 --port 7081 &
+CORTEX_PID=$!
+
+# Wait for Cortex to be ready
+echo "⏳ Waiting for Cortex to be ready..."
+for i in {1..30}; do
+    if curl -sf http://localhost:7081/_health > /dev/null 2>&1; then
+        echo "✅ Cortex is ready!"
+        break
+    fi
+    if [ $i -eq 30 ]; then
+        echo "❌ Cortex failed to start within 30 seconds"
+        exit 1
+    fi
+    sleep 1
+done
+
+# Start Relay (Node.js/Express) in the foreground
+echo "🔌 Starting Relay on port 7078..."
+cd /app/relay
+exec node server.js
+
+# Note: We exec the last process so signals get forwarded properly
+# If Relay dies, the container stops. If Cortex dies, Relay will fail too.