Enables dagpipe wiki on the docs hub alongside lib and mcp, removes stale nested lib pages, and picks up regenerated GSDFC docstrings in the MCP bundle.
- collect.py copies each repo's built site contents directly to a
top-level <repo>/ dir (was libs|apis|wiki/<repo>/site nesting)
- nginx uses `index index.html lib/index.html api/index.html` so
/dagpipe/ -> lib/index.html, /auth-server/ -> api/index.html are
served internally with no redirects
- _index regenerates links against the flat layout
(/dagpipe/lib/, /auth-server/api/, /mongo-ops/, /blog/...)
- config.yml static entries point at vendored blog/ + media-manager/
- Dockerfile copies per-repo dirs flat into the nginx html root
- removed stale libs/, apis/, wiki/, tutorials/ category trees
