- CLAUDE.md: add SensitiveKeysConfig, SensitiveKeysRepository, SensitiveKeysMerger to core admin classes; add SensitiveKeysAdminController endpoint; add PostgresSensitiveKeysRepository; add sensitive keys convention; add admin page to UI structure - Design spec and implementation plan for the feature Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>