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/k3s/forgejo/service.yaml

@@ -0,0 +1,13 @@
+apiVersion: v1
+kind: Service
+metadata:
+  name: forgejo-app-service
+  namespace: forgejo
+spec:
+  selector:
+    app: forgejo-app
+  ports:
+    - name: web
+      protocol: TCP
+      port: 3000
+      targetPort: 3000