Use internal PyPI proxy in Dockerfile

Dockerfile

@@ -21,6 +21,8 @@ RUN npm run build
 # Runtime stage
 FROM containers.global.bsf.tools/python:3.12-slim
 
+ARG PIP_INDEX_URL=https://deps.global.bsf.tools/artifactory/api/pypi/pypi.org/simple
+
 # Disable proxy cache
 RUN printf 'Acquire::http::Pipeline-Depth 0;\nAcquire::http::No-Cache true;\nAcquire::BrokenProxy true;\n' > /etc/apt/apt.conf.d/99fixbadproxy
 
@@ -38,7 +40,7 @@ WORKDIR /app
 
 # Copy requirements and install Python dependencies
 COPY backend/requirements.txt .
-RUN pip install --no-cache-dir -r requirements.txt
+RUN pip install --no-cache-dir --index-url "$PIP_INDEX_URL" -r requirements.txt
 
 # Copy backend source
 COPY backend/ ./backend/