Comprehensive CLAUDE.md and AGENTS.md update

[ihabadham]

Follow-up after the Pro RSC migration (#727).

Current state

• CLAUDE.md (56 lines): single topic — Conductor Compatibility wrapper (bin/conductor-exec). No coverage of project architecture, Rails patterns, React conventions, ReScript, Stimulus, comments DB, build system, or anything else.
• AGENTS.md (12 lines): two short sections (Project Overview + Working Rules). Project Overview line was factually outdated by Pro RSC migration: tutorial on React on Rails Pro with a React Server Components demo #727 (still references "react_on_rails gem" without Pro / NodeRenderer / RSC).

Goal

Make both docs map to the actual project surface so future agents (Claude, Codex, GPT, others) can pick up tasks without needing to grep their way through the codebase first.

Suggested scope

• Architecture map: client / server SSR / RSC bundles, the Pro Node Renderer, the auto-bundling registration flow.
• Conventions: ROR component placement (ror_components/ for auto-bundling), 'use client' directive rules for entry-point modules, controller-props pattern for RSC data fetching.
• Build / dev: env-var dispatch (`RSC_BUNDLE_ONLY`, `SERVER_BUNDLE_ONLY`), the six `Procfile.dev` processes, where the RSC demo lives.
• Testing: where request specs and system specs live, how rspec / lint workflows trigger.
• Deployment: Control Plane + Pro license env vars, review-app provisioning trigger.
• Existing topics already in CLAUDE.md (Conductor Compatibility) — keep, don't replace.

Why deferred

A correctness-only patch on AGENTS.md or a Pro/RSC-only addition to CLAUDE.md would leave both docs lopsided. A comprehensive overhaul is the right shape and is out of scope for the migration PR.