Add .dockerignore file and update Dockerfile to use Alpine images for Node.js and Python with SHA256

Dockerfile

@@ -1,5 +1,11 @@
+# Build arguments
+ARG NODE_VERSION=20
+ARG NODE_ALPINE_SHA256=sha256:6a91081a440be0b57336fbc4ee87f3dab1a2fd6f80cdb355dcf960e13bda3b59
+ARG PYTHON_VERSION=3.11
+ARG PYTHON_ALPINE_SHA256=sha256:822ceb965f026bc47ee667e50a44309d2d81087780bbbf64f2005521781a3621
+
 # Build the frontend
-FROM node:20-bookworm-slim AS build-frontend
+FROM node:${NODE_VERSION}-alpine@${NODE_ALPINE_SHA256} AS build-frontend
 
 WORKDIR /src
 
@@ -13,13 +19,15 @@ RUN npm install --omit=dev && \
   npm run build-frontend
 
 # Main app build
-FROM python:3.11-bookworm
+FROM python:${PYTHON_VERSION}-alpine@${PYTHON_ALPINE_SHA256}
 
 WORKDIR /app
 
 # Install Python deps
 COPY ./requirements.txt .
-RUN pip install -r requirements.txt
+RUN apk add --no-cache --virtual .build-deps gcc musl-dev && \
+    pip install -r requirements.txt && \
+    apk del .build-deps
 
 # Copy prebuilt frontend
 COPY --from=build-frontend /src/public public