Sync AGENTS.md, CLAUDE.md, and .claude/rules from updated project_rules
templates: workplan-first session protocol, legacy terminology footnote,
and GET /workplans/ examples.
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>