GHSA-hm8q-7f3q-5f36

### Summary

Improper validation of the JWT NumericDate claims `exp`, `nbf`, and `iat` in `hono/utils/jwt` allows tokens with non-spec-compliant claim values to silently bypass time-based checks. This issue is not exploitable by an anonymous attacker; it only manifests when a malformed claim value reaches `verify()` — typically when the application itself issues such tokens, or when the signing key is otherwise under attacker control.

### Details

The validation routine combined option, presence, and threshold checks in a single short-circuiting expression, so several classes of malformed values were silently skipped instead of rejected:

- A falsy numeric value short-circuited the presence check. - A non-finite numeric value compared as never-after-now and never-expired. - A non-numeric type produced NaN comparisons that evaluated false.

This deviates from RFC 7519 §4.1.4, which defines NumericDate as a finite JSON numeric value.

### Impact

An actor able to issue tokens accepted by the application may craft tokens whose `exp`, `nbf`, or `iat` claims silently bypass time-based enforcement. This may lead to:

- Tokens treated as never expiring even with `exp` configured on the verifier. - Tokens with a future `nbf` accepted as currently valid. - Tokens with a future `iat` accepted as legitimately issued.

Deployments using a well-formed token issuer and protecting the signing key are not affected.