Feat
- vector: meter the stale-chunk prune delete (#1399 review r2)
Fix
- vector: resolve placeholder-vs-index by rule, not by scroll order
- vector: never fail a successful index on a prune error (#1399 review)
- vector: prune stale chunk points so re-indexing converges
Perf
- vector: run the placeholder/index lookups concurrently (#1399 review r4)