Add Template to deploy forgejo.

This template allows deploying a forgejo en either Scaleway or Hetzner
(untested) without much knowledge about them.
It DOES require knowledge about Terragrunt and ansible. A wizard of
sorts is provided but it will not guarantee success without some
knowledge about the underlying technology.

ansible/roles/forgejo/templates/docker-compose.monitoring.yml.j2

@@ -0,0 +1,27 @@
+# Docker Compose override for Prometheus monitoring
+# Generated by Ansible
+# This file extends the main docker-compose.yml
+
+services:
+  prometheus:
+    image: prom/prometheus:latest
+    container_name: prometheus
+    restart: unless-stopped
+    volumes:
+      - ./monitoring/prometheus.yml:/etc/prometheus/prometheus.yml:ro
+      - ./monitoring/data:/prometheus
+    command:
+      - '--config.file=/etc/prometheus/prometheus.yml'
+      - '--storage.tsdb.path=/prometheus'
+      - '--storage.tsdb.retention.time=15d'
+      - '--web.enable-lifecycle'
+    ports:
+      # Only bind to localhost for security - not exposed externally
+      - "127.0.0.1:{{ prometheus_port | default(9090) }}:9090"
+    networks:
+      - forgejo-network
+
+networks:
+  forgejo-network:
+    external: true
+    name: {{ forgejo_base_path | basename }}_default