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>

README.md

@@ -35,7 +35,6 @@
 │  └── Headscale (8085) - VPN mesh       │
 ├─────────────────────────────────────────┤
 │  Monitoring Layer                       │
-│  ├── Uptime Kuma (3001) - Uptime       │
 │  ├── Netdata (19999) - Metrics         │
 │  └── Organizr (8084) - Dashboard       │
 ├─────────────────────────────────────────┤
@@ -134,7 +133,6 @@ See [External Services](docs/EXTERNAL_SERVICES.md) for services maintained in se
 | **Organizr** | 8084 | Unified dashboard |
 | **Headscale** | 8085 | VPN control server |
 | **Jellyfin** | 8096 | Media streaming |
-| **Uptime Kuma** | 3001 | Service monitoring |
 | **Gitea** | 3002 | Git repository hosting |
 | **Gitea SSH** | 2222 | Git SSH access |
 | **PostgreSQL Shared** | 5432 | Shared database (internal) |