docs: add RFC 0005 for radarctl deployment CLI

[yatharthranjan]

Summary

This PR adds RFC 0005 proposing radarctl, a Go CLI tool to improve the deployment experience for RADAR-Kubernetes.

Problem

Deploying RADAR-Kubernetes today requires manually editing 3+ YAML files with no validation, understanding complex mods/ composition, and diagnosing failures across ~30 Helm releases with raw kubectl commands. There is a steep entry barrier for researchers and first-time operators.

Proposed solution

radarctl — a single Go binary at cli/ in the RADAR-Kubernetes repo — with five commands:

• radarctl init — prerequisites check + setup wizard (3 modes: wizard, interactive, expert)
• radarctl deploy — helmfile sync with live progress, validation, and post-deploy health checks
• radarctl status — unified health dashboard across all releases
• radarctl diagnose — full diagnostic snapshot for agentic/CI debug loops
• radarctl validate — standalone config validation

The wizard encodes institutional knowledge: high-level toggles ("Enable Fitbit?") expand into all required config values, only prompting for secrets it cannot infer.

All commands support -o json and consistent exit codes for use in CI pipelines and AI agent loops.

Checklist

• RFC follows rfcs/0000-template.md structure
• Placed under rfcs/platform/ (platform-level deployment tooling)
• All template sections completed
• Open questions documented

[pvannierop]

@yatharthranjan Do you plan to have the CLI interface with helmfile?

[yatharthranjan]

hi Pim, yes the deploy part with interface with helmfile (see in the description above)

[afolarin]

Real nice 👍🏽
Minor one -- we should have -h/--help to provide convenience command/subcommand usage/docs.