3 plans in 2 waves covering all 5 SECU requirements: - Plan 01 (W1): Security service foundation (JWT, Ed25519, bootstrap token) - Plan 02 (W2): Spring Security filter chain, endpoint protection, test adaptation - Plan 03 (W2): SSE payload signing with Ed25519 Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>