feat: initial health-app with Express API and GitOps CI/CD

Node.js Express app with /health, /ready, / endpoints.
Multi-stage Dockerfile, GitHub Actions pipeline for GHCR push
and gitops-infra manifest auto-update.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

package.json

@@ -0,0 +1,17 @@
+{
+  "name": "@infinicaretech/health-app",
+  "version": "1.0.0",
+  "private": true,
+  "description": "Production-ready health check API for GitOps deployment",
+  "main": "src/server.js",
+  "scripts": {
+    "start": "node src/server.js",
+    "dev": "node --watch src/server.js"
+  },
+  "dependencies": {
+    "express": "^4.21.2"
+  },
+  "engines": {
+    "node": ">=20.0.0"
+  }
+}