Add Google Cloud K3s infrastructure support

- Add Terraform configuration for GCP instance and storage
- Add startup script for K3s installation and configuration
- Add pipeline scripts for deployment and management
- Add Forgejo deployment manifests and configuration

gcloud/tf/scripts/cert-manager/install_cert-manager.sh

@@ -0,0 +1,11 @@
+#!/usr/bin/env bash
+
+if kubectl -n cert-manager get pods 2>/dev/null | grep -q 'Running'; then
+    echo "cert-manager pods already running. Skipping installation."
+    exit 0
+fi
+
+
+
+
+kubectl apply -f https://github.com/cert-manager/cert-manager/releases/download/v1.17.2/cert-manager.yaml