Use fast-grep (`fgr`) for regex and literal text search across this repository.
When an index exists it is dramatically faster than `grep`/`ripgrep`; without an
index it is comparable to ripgrep. TRIGGER when: searching for code (function,
symbol, identifier, string), counting occurrences, or listing files matching a
pattern in this repo. SKIP for: git-history search (use `git log -G`/`git grep`),
binary files, or patterns that require lookaround / backreferences (the Rust
`regex` crate does not support them — fall back to `rg -P` or `grep -P`).
2026-05-01