Add custodian integration scaffold

CLAUDE.md modular rules, AGENTS/INTENT/SCOPE/.custodian-brief, and the
state-hub bootstrap workplan (WHYNOT-WP-0001).

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

SCOPE.md

@@ -0,0 +1,32 @@
+# SCOPE
+
+> This file was generated by `statehub register`. Refine it as the repository
+> boundaries become clearer.
+
+## One-liner
+
+The neutral, mostly-black-and-white visual language for **whynot** — Tegwick's prototype and market-signal organisation.
+
+## Core Idea
+
+whynot-design exists to provide the capability described in INTENT.md.
+
+## In Scope
+
+- Maintain the repository's primary implementation.
+- Keep docs, tests, and operational metadata current.
+
+## Out of Scope
+
+- Own unrelated adjacent systems.
+- Make irreversible operational decisions without human approval.
+
+## Current State
+
+- Status: active; implementation and stability should be verified by the repo agent.
+
+## Getting Oriented
+
+- Start with: INTENT.md
+- Agent instructions: AGENTS.md
+- Workplans: workplans/