Find-in-files / replace (T-52/T-53) run as an in-process isolate-pool
grep engine behind an engine-agnostic search.grep verb — not pql (its
search is a ranked document index, with no line numbers, regex, or
glob) and not a ripgrep shell-out (unvendored, not guaranteed
cross-platform). ripgrep is kept as a future optional accelerator
behind the same verb. Clarifies the D-3 wrap-pql boundary: content
grep is a code-navigation primitive pql does not offer.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>