fix: hardcode Traefik port labels (Gotcha 6 - vars not expanded in labels)

Coolify does not expand ${VAR} in label values. All loadbalancer port
labels must use hardcoded values:
- trilium:   ${TRILIUM_HTTP_PORT}  → 8080
- adguard:   ${ADGUARD_HTTP_PORT}  → 80
- authentik: ${AUTHENTIK_HTTP_PORT} → 9000
- gitea:     ${GITEA_HTTP_PORT}    → 3000
- wireguard: ${WG_UI_PORT}         → 51821

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

authentik/stack.env

@@ -19,7 +19,7 @@ AUTHENTIK_SECRET_KEY=
 AUTHENTIK_BOOTSTRAP_EMAIL=
 AUTHENTIK_BOOTSTRAP_PASSWORD=
 AUTHENTIK_BOOTSTRAP_TOKEN=
-AUTHENTIK_HTTP_PORT=
+AUTHENTIK_HTTP_PORT=9000
 
 ##### Traefik / dominios #####
 TRAEFIK_DOCKER_NETWORK=