adventurelog: fix lying frontend healthcheck (wget in a distroless image)

The frontend healthcheck ran 'wget --spider', but the image is distroless: no
shell, no wget, no curl, and node itself is only reachable at an absolute path
(/nodejs/bin/node, off PATH). The probe therefore ENOENT'd on every run, the
container stayed permanently unhealthy, and Traefik -- which will not route to
an unhealthy container -- returned 404 to the customer even though the app was
serving 200 on :3000 the whole time.

Replaced with the Node-exec family using the absolute interpreter path.
Live-verified on the demo box.

Campaign 7 catalog sweep.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Nn3VgQk9iwEGgyx6QJ2NvE

templates/adventurelog/docker-compose.yml

@@ -88,7 +88,11 @@ services:
         limits:
           memory: 256M
     healthcheck:
-      test: ["CMD", "wget", "--spider", "-q", "http://127.0.0.1:3000"]
+      # A frontend image distroless: nincs benne shell, wget vagy curl — a node
+      # bináris is csak abszolút úton érhető el (nem a PATH-on). A korábbi wget
+      # próba ezért soha nem futott le, a konténer véglegesen unhealthy lett, és
+      # a Traefik nem irányított rá forgalmat (404 az ügyfélnek).
+      test: ["CMD", "/nodejs/bin/node", "-e", "fetch('http://127.0.0.1:3000').then(r=>process.exit(r.ok?0:1)).catch(()=>process.exit(1))"]
       interval: 10s
       timeout: 5s
       retries: 5