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>

.custodian-brief.md

@@ -0,0 +1,27 @@
+<!-- custodian-brief: generated by statehub register; fix-consistency may replace this file -->
+# Custodian Brief - whynot-design
+
+**Project:** whynot-design
+**Domain:** infotech
+**State Hub:** http://127.0.0.1:8000
+**Topic ID:** `cee7bedf-2b48-46ef-8601-006474f2ad7a`
+
+## Open Workplans
+
+### Bootstrap State Hub integration
+
+Workplan file: `workplans/WHYNOT-WP-0001-statehub-bootstrap.md`
+
+Open tasks:
+- T01 - Review generated integration files
+- T02 - Verify local developer workflow
+- T03 - Seed first real workplan
+
+## Session Start
+
+1. Read `INTENT.md`, `SCOPE.md`, and `AGENTS.md`.
+2. Check inbox: `GET /messages/?to_agent=whynot-design&unread_only=true`.
+3. Scan `workplans/`.
+4. Update task statuses in workplan files as work progresses.
+
+Last generated: 2026-06-22