Replace manual chi/TLS/http.Server setup with httpserver.New which
provides TLS 1.3, config-driven timeouts, and the chi router. Replace
local loggingMiddleware and statusWriter with mcdsl equivalents.
Seal-aware middleware (requireUnseal, requireAuth, requireAdmin) and
token extraction remain metacrypt-specific.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>