fix(stalwart): disable healthcheck — distroless image has no wget

Stalwart's official Docker image is distroless and has no wget, curl,
nc, ss, or netstat. The compose healthcheck (CMD wget ...) was failing
with "executable file not found" since 2026-05-05; container shows
status=unhealthy 24/7 even though Stalwart itself runs fine on
:25 / :587 / :465 / :993 / :8080.

Disable. Crash detection comes from docker's restart=always plus
mana-monitoring's external SMTP probe (blackbox-exporter), not from
inside the container.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

docker-compose.macmini.yml

@@ -686,12 +686,14 @@ services:
       - stalwart_data:/opt/stalwart-mail
     environment:
       - STALWART_ADMIN_PASSWORD=${STALWART_ADMIN_PASSWORD:-ChangeMe123!}
+    # Stalwart's official image is distroless — no wget, curl, nc, ss,
+    # netstat. Any `docker exec`-based healthcheck just OOMs with
+    # "executable file not found". Deactivate; rely on docker's
+    # `restart: always` if Stalwart's process actually crashes
+    # (mana-monitoring will catch the SMTP-port-unreachable case via
+    # blackbox-exporter from outside the container).
     healthcheck:
-      test: ["CMD", "wget", "-q", "--spider", "http://localhost:8080/healthz"]
-      interval: 120s
-      timeout: 5s
-      retries: 3
-      start_period: 10s
+      disable: true
 
   mana-crawler:
     build: