feat: add dockcheck auto-update labels to remaining services

Add mag37.dockcheck.update labels to enable automated container update monitoring for:
- Gotify iOS assistant service
- Karakeep (Hoarder) bookmark manager and all components (Chrome, Meilisearch)
- MMDL task management service
- Postiz social media scheduler and all components (PostgreSQL, Redis)

This completes the rollout of dockcheck labels across all Docker services for consistent update monitoring.

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

roles/docker/templates/hoarder-compose.yml.j2

@@ -22,12 +22,14 @@ services:
       glance.url: https://{{ subdomains.bookmarks }}/
       glance.description: Bookmark manager
       glance.id: karakeep
+      mag37.dockcheck.update: true
   chrome:
     image: gcr.io/zenika-hub/alpine-chrome:123
     restart: unless-stopped
     labels:
       glance.name: Chrome
       glance.parent: karakeep
+      mag37.dockcheck.update: true
     command:
       - --no-sandbox
       - --disable-gpu
@@ -41,6 +43,7 @@ services:
     labels:
       glance.name: Meilisearch
       glance.parent: karakeep
+      mag37.dockcheck.update: true
     env_file:
       - .env
     environment: