feat: add Docker deployment configuration

Add backend and frontend Dockerfiles, docker-compose setup with nginx
reverse proxy, .dockerignore files and Makefile for dev/prod workflows.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

backend.Dockerfile

@@ -0,0 +1,19 @@
+FROM python:3.12-slim
+
+RUN apt-get update && \
+    apt-get install -y --no-install-recommends poppler-utils && \
+    rm -rf /var/lib/apt/lists/*
+
+COPY --from=ghcr.io/astral-sh/uv:latest /uv /uvx /bin/
+
+WORKDIR /app
+
+COPY pyproject.toml uv.lock ./
+RUN uv sync --frozen --no-dev --no-install-project
+
+COPY src/ src/
+RUN uv sync --frozen --no-dev
+
+EXPOSE 8000
+
+CMD ["uv", "run", "plesna-gerance", "serve", "--host", "0.0.0.0"]