A more specific query used to drop the exact match: the token-OR filter
recalled every entry sharing one token, the sort used confidence alone,
and the default --limit cut silently. Entries now rank by how many
distinct query tokens they match, then confidence, then recency, and a
query that matched more than fit says '-- N more matched, raise --limit
to see them'. The hit count lives in a local map so a field stored on
disk can never become a sort key, and the type grouping uses a
null-prototype map so a row typed 'constructor' or '__proto__' cannot
crash the run. Ranking code ported from #2796; regression vectors
adapted from #2799 (its stemmer is not needed).
Co-authored-by: loulanyue <260355617@qq.com>
Co-authored-by: y$un_ <forrest.sun527@gmail.com>
