Optimize deployment and improve package.json

deployment/Dockerfile.backend

@@ -1,19 +1,25 @@
+# 1. Install pip dependencies
 FROM python:3.12 AS builder
 
 WORKDIR /app
 RUN python3 -m venv .venv
 COPY backend/requirements.txt .
-RUN ./.venv/bin/pip3 install -r requirements.txt
+RUN --mount=type=cache,target=/root/.cache/pip \
+    ./.venv/bin/pip3 install -r requirements.txt
 
+# 2. Runtime stage
 FROM python:3.12-slim AS runtime
 
+# 2.1. Non-root user
 WORKDIR /app
 RUN useradd -u 1000 app && \
     chown -R app /app
 USER app
 
+# 2.2. Copy content and create dirs
 COPY --chown=app backend .
 COPY --from=builder --chown=app /app/.venv .venv
 RUN mkdir -p /app/data
 
+# 3. Final command
 ENTRYPOINT exec ./.venv/bin/fastapi run --port ${PORT:-8300} main.py