Next.js App Router doesn't match DELETE/PUT on /api/docs/route.ts for
nested paths; need a dynamic segment. POST stays at /api/docs, PUT+DELETE
move to /api/docs/[...slug]. Verified DELETE works locally + via Caddy.
Web UI login sets mcpedia_admin cookie; /api/docs/route.ts required the
x-webhook-secret header which the browser form also sends, but the dual-auth
path was brittle. Now accepts either: header (API/MCP style) OR cookie (web
login). Also set ADMIN_PASSWORD on VPS .env and restart web.