Probe CHaP doc sites instead of hardcoding per-package URLs
Replace the name-based PREFIX_RULES (6 entries) and most of the EXACT_OVERRIDES table (26 -> 14 entries) with a heuristic: for each CHaP package, generate candidate subdomains under *.cardano.intersectmbo.org by progressively dropping trailing '-<token>' segments of the package name, then HEAD-probe doc-index.html at each candidate and take the first that resolves. doc-index.html is a Haddock-standard asset that every real package serves and that wrong-site probes reliably 404 on. That makes the heuristic safe: mis-guesses become NONE (stripped link) rather than wrong-but-not-broken URLs. EXACT_OVERRIDES retains only packages whose subdomain is not a name-suffix (the cardano-base family at base.cardano.intersectmbo.org, the ledger-repo members that don't start with 'cardano-ledger-', the two ouroboros-network oddballs, and io-classes on GitHub Pages). Defensive entries for packages not currently referenced by this project's Haddocks have been dropped; they can be added when new re-exports surface them (Phase 7's dead-link annotation means missing entries don't break the build).