v0.3.0

Other

• mark Error #[non_exhaustive]
• declare bidi feature dependency (fixes component-subsets CI)
• enforce VerifyDnsLength (reject empty/trailing-root labels)
• apply UTS #39 augmented (CJK) script sets in is_single_script
• satisfy CI gates for security fixes (fmt, clippy, public-api snapshot)
• resolve is_single_script via Script_Extensions intersection (UTS #39)
• IDNA tests: adapt to fallible to_unicode; raise conformance rejection bar to 480
• enforce full IDNA2008 validity (CheckBidi/ContextJ/Hyphens/V1/V5/V6) and re-canonicalize xn--
• do not drop combining marks past MAX_COMBINING in NFC recomposition
• O(1) matched-PDI lookup (latent quadratic)
• linear find/contains (quadratic-scan DoS)
• avoid O(n) Vec::remove in discontiguous matching
• strip Default_Ignorable code points in UTS #39 skeleton (confusable-detection miss)
• cap MessageFormat parse recursion depth (stack-overflow DoS)
• use checked arithmetic in POSIX TZ offset parsing (i32 overflow panic/wrap)
• cap punycode decode output (decompression-bomb DoS) and enforce 253-octet domain limit