Stop linking non-CHaP packages; mark them unclickable
Cross-package hrefs to non-CHaP packages (base, bytestring, time, the
transformers stack, etc.) were being rewritten to Hackage URLs. In
practice:
- Readers of cardano-api docs rarely click into bootlib internals.
- Haddock's per-module URL structure (including src/ source views
and '-<version>-inplace' suffixes from local rebuilds) doesn't
line up cleanly with Hackage's rendering, so most of these URLs
fail validation and become dead-link spans anyway.
The Hackage rewrites were therefore mostly producing 404s without
adding reader value. Treat non-CHaP just like unmapped CHaP: emit an
unclickable <span> with a tooltip, no outbound link. Track the count
in a separate NON_CHAP bucket so it's visible in the summary but does
not contribute to strict-mode failure (it's a policy choice, not a
gap).