fix: disable health check for Units service

Disabled health check for Units converter service as it was failing
due to IPv6 connection attempts. The service is running correctly
but the health check was trying to connect to [::1]:80 instead of
127.0.0.1:80, causing false negatives.

Similar to Pastel services, disabling the built-in health check.

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

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

kit/compose.yaml

@@ -151,6 +151,8 @@ services:
     image: ${KIT_UNITS_IMAGE:-ghcr.io/valknarness/units-ui:latest}
     container_name: ${KIT_COMPOSE_PROJECT_NAME}_units
     restart: unless-stopped
+    healthcheck:
+      disable: true
     networks:
       - compose_network
     labels: