feat: Add Chat endpoint and fix Dockerfile

Dockerfile

@@ -9,13 +9,13 @@ RUN apt-get update && apt-get install -y \
     && rm -rf /var/lib/apt/lists/*
 
 # Copy requirements
-COPY backend/requirements.txt .
+COPY requirements.txt .
 
 # Install Python dependencies
 RUN pip install --no-cache-dir -r requirements.txt
 
 # Copy application code
-COPY backend/ .
+COPY src/ ./src/
 
 # Expose port
 EXPOSE 7860