fix: describe exclusive min and max validation failures

[FanWu-ai]

Summary

Exclusive min and max refinements currently lose their explanatory error messages because || message binds only to the false branch of the conditional expression. For example, validate(11, max(number(), 10, {exclusive: true})) returns a generic refinement error without the bound.

Group the comparison expression before its error-message fallback. Acceptance, coercion, type signatures and dependencies are unchanged. Twelve regressions/controls cover numbers, dates, exact boundaries, inclusive messages and nested custom-error causes; six fail on the original source.

Validation

On Node 24.19.0 and 22.19.0, pristine full suite 225 passes; final 237 passes. Required npm test (build and source/test types included), npm run lint (configured ESLint and whole-project Prettier), package build and diff checks pass. Additional 1,572 scenarios per runtime and 624 independent review cases pass.

Two environment/check qualifications:

• The reused dependency tree retains an existing expect 29.7 compatibility resolution for wildcard @types/expect; this patch makes no dependency change. A fresh unpinned CI install may differ.
• Supplemental direct-file ESLint, beyond the configured required lint command, reports five existing no-shadow findings elsewhere in refinements.ts. Pristine and final findings are identical at the same locations; the new test has none. That supplemental check is not claimed passed.

Other CI runtimes and hosted results are not claimed. Prepared and tested with AI assistance (OpenAI Codex); no human review is claimed.