Add hit counter service and expand frontend content sections

- New hit-counter FastAPI service (Prometheus metrics, SQLite storage), wired into Caddy (hits.carloselugo.com) and docker-compose
- Scrape hit-counter in Prometheus every 5m
- Add articles, about, contact, experience, and expertise sections to the frontend, with per-article hit tracking

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

hit-counter/Dockerfile

@@ -0,0 +1,6 @@
+FROM python:3.12-slim
+WORKDIR /app
+RUN pip install --no-cache-dir fastapi uvicorn[standard] prometheus_client
+COPY main.py .
+EXPOSE 8000
+CMD ["uvicorn", "main:app", "--host", "0.0.0.0", "--port", "8000"]