feat: add quickstart manifest schema, RAG manifest, and containerized installer for Project Navigator support

[gurvinder]

Summary

• Adds a JSON Schema (quickstart-manifest.schema.json) defining the standard structure for Navigator quickstart manifests
• Adds the RAG quickstart manifest (quickstart-manifest.yaml) with full metadata, lifecycle actions, prerequisites, and parameter definitions
• Adds a containerized installer (installer/) that runs as a Kubernetes Job to perform lifecycle actions (check_pre_reqs, install, status, upgrade, uninstall) via Helm against a target namespace
• Installer image is built on UBI9 with oc, helm, jq, and yq, and packages the RAG Helm chart at build time
• Includes deploy.sh as a local proxy script that creates RBAC, launches the installer Job, monitors logs, retrieves the termination message, and cleans up

Test Results

All lifecycle actions were tested on OpenShift 4.21.16 against the llama-stack-rag namespace using image quay.io/rh-ai-quickstart/rag-installer:0.2.38.

#	Action	Result	Log
1	check_pre_reqs	Job completed successfully. All prerequisites validated (OCP 4.21.16, 19 workers, 229 CPU, 927 GiB, 11 GPU nodes, storage classes, ODH CRDs).	check_pre_reqs_output.log
2	status (before install)	Job completed successfully. Correctly reported "Namespace llama-stack-rag does not exist — no deployment found."	status_before_output.log
3	install (interactive)	Job completed successfully. Helm release deployed (revision 1). llamastack ready after ~150s. RAG UI endpoint returned.	install_interactive_output.log
4	status (after install)	Job completed successfully. Reported 14 ready pods, 16 services, 5 routes, 5 bound PVCs.	status_after_output.log
5	termination message	Structured JSON termination message correctly written to pod and Job annotation. Includes status, action, namespace, and logConfigMap reference.	termination_msg_output.log
6	log ConfigMap	ConfigMap persisted with full installer logs. ConfigMaps labeled with app=rag-installer and target-namespace.	log_configmap_output.log
7	upgrade	Job completed successfully. Helm release upgraded (revision 2). Old pipeline jobs cleaned up. llamastack ready immediately. Endpoint returned.	upgrade_output.log
8	uninstall_delete_all	Job completed successfully. Namespace and all resources removed.	uninstall_delete_all_output.log