Force Docker cache bust to rebuild with new requirements

Dockerfile

@@ -17,6 +17,9 @@ RUN apt-get update && apt-get install -y \
 # Copy requirements first for better caching
 COPY requirements.txt .
 
+# Cache bust - change this value to force rebuild
+ARG CACHEBUST=3
+
 # Install Python dependencies
 RUN pip install --no-cache-dir --upgrade pip && \
     pip install --no-cache-dir -r requirements.txt