Add dokploy-prom-monitoring-extension template with comprehensive tests and documentation (#548)

* Add dokploy-prom-monitoring-extension template with comprehensive tests and documentation

* Fix METRICS_CONFIG environment variable: use single-line JSON format

* Fix template.toml: use correct [config.env] syntax for environment variables

* Fix docker-compose.yml: add env_file reference to load environment variables

* Delete blueprints/dokploy-prom-monitoring-extension/README.md

* Delete test-dokploy-prom-monitoring-extension.sh

---------

Co-authored-by: Sanjeevi Subramani <ssanjeevi.ss@gmail.com>
Co-authored-by: Mauricio Siu <47042324+Siumauricio@users.noreply.github.com>

meta.json

@@ -1830,6 +1830,26 @@
       "document-signing"
     ]
   },
+  {
+    "id": "dokploy-prom-monitoring-extension",
+    "name": "Dokploy Prometheus Monitoring Extension",
+    "version": "canary",
+    "description": "Dokploy monitoring extension with Prometheus metrics export for external monitoring systems like Grafana Cloud. Tracks server and container metrics with configurable thresholds and alerting.",
+    "logo": "logo.svg",
+    "links": {
+      "github": "https://github.com/Dokploy/dokploy",
+      "website": "https://dokploy.com/",
+      "docs": "https://docs.dokploy.com/"
+    },
+    "tags": [
+      "monitoring",
+      "prometheus",
+      "metrics",
+      "observability",
+      "docker",
+      "grafana"
+    ]
+  },
   {
     "id": "domain-locker",
     "name": "Domain Locker",