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>

Caddyfile

@@ -168,3 +168,26 @@ tools.carloselugo.com {
         format json
     }
 }
+
+# ── Void — void.carloselugo.com ───────────────────────────────────────────────
+void.carloselugo.com {
+    import security_headers
+    root * /srv/void
+    file_server
+    encode gzip
+    log {
+        output file /var/log/caddy/void.log
+        format json
+    }
+}
+
+# ── Hit Counter — hits.carloselugo.com ────────────────────────────────────────
+hits.carloselugo.com {
+    import security_headers
+    reverse_proxy hit-counter:8000
+    encode gzip
+    log {
+        output file /var/log/caddy/hit-counter.log
+        format json
+    }
+}