chore(deps): bump criterion 0.5→0.8 (#33)

Supersedes Dependabot #18 (could not merge: siblings #20/#21/#23 each
rewrote Cargo.lock). Resolved via cargo update.

Co-authored-by: Jonathan D.A. Jewell <67598845+hyperpolymath@users.noreply.github.com>
Co-authored-by: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: 3 people

Cargo.lock

@@ -65,7 +65,7 @@ rfd = "0.17"
 
 # Testing
 tempfile = "3"
-criterion = { version = "0.5", features = ["html_reports"] }
+criterion = { version = "0.8", features = ["html_reports"] }
 
 # Internal crates
 presswerk-core = { path = "crates/presswerk-core" }