Type-checking performance

Choose the number of checker workers in each Corsa process:

vpx vize check --checkers 4 --servers 1

--checkers accepts a positive integer and overrides VIZE_CHECKERS. Without either setting, Vize uses one checker worker. --servers controls separate Corsa processes; automatic server sizing accounts for the number of checker workers in each process.

The one-worker default preserves the diagnostic behavior established in #3905. Wider Corsa pools produced missing and different diagnostics in that comparison. Opt into a wider pool when that tradeoff is acceptable for your workflow.

Rust callers can use BatchTypeChecker::set_checker_count(Some(4)) or CorsaExecutor::set_checker_count(Some(4)) without changing process-wide environment variables. Passing None restores the environment/default selection.

To inspect where a run spends its time:

vpx vize check --profile

Alias dependency collection shares Vue-free closure results within each run. Changes are read again on the next collection.