feat: add Docker healthchecks, remove Uptime Kuma

- Add healthcheck configurations to 13 stacks for Portainer status monitoring
- Remove Uptime Kuma service (replaced by Docker healthchecks)
- Clean up stale Heimdall references
- Update documentation and service counts

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

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

stacks/core-api.yml

@@ -5,11 +5,11 @@ version: '3.8'
 # Port: 8083 (HTTP API)
 # Network: docker-dataplane (shared infrastructure network)
 #
-# Container image built from: git.schweitz.net/jpmschweitzer/core-api
+# Container image built from: tower-of-joy:3002/jpmschweitzer/core-api (internal registry)
 
 services:
   core-api:
-    image: git.schweitz.net/jpmschweitzer/core-api:latest
+    image: tower-of-joy:3002/jpmschweitzer/core-api:latest
     container_name: core-api
     restart: unless-stopped
 
@@ -56,11 +56,6 @@ services:
       - WEB_SCRAPER_DEFAULT_MAX_LENGTH=10000
       - WEB_SCRAPER_MAX_LINKS_TO_EXTRACT=50
 
-      # Uptime Kuma Configuration
-      - KUMA_URL=http://uptime-kuma:3001
-      - KUMA_USERNAME=${KUMA_USERNAME}
-      - KUMA_PASSWORD=${KUMA_PASSWORD}
-
       # Python path
       - PYTHONPATH=/app