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>

prometheus/prometheus.yml

@@ -14,3 +14,8 @@ scrape_configs:
   - job_name: "cadvisor"
     static_configs:
       - targets: ["cadvisor:8080"]
+
+  - job_name: "hit-counter"
+    scrape_interval: 5m
+    static_configs:
+      - targets: ["hit-counter:8000"]