fix: reject Unicode whitespace in recovery URLs

[soulteary]

Summary

• reject malformed UTF-8 before URL parsing
• reject Unicode separator characters and U+0085 in addition to the existing ASCII whitespace/control range
• retain valid UTF-8 path support instead of banning non-ASCII input wholesale
• add cases for NBSP, NEL, em space, line separator, paragraph separator, invalid UTF-8, and a valid Unicode path

Validation

• git diff --check
• the existing PHP test suite will execute the new cases in CI

Follow-up to the recovery URL validation review in #22.

[chatgpt-codex-connector]

Codex Review Summary

This comment shows the latest Codex review activity on this pull request.

Review	Status	Commit	Review trigger
📝 Code Review	✅ Completed 2026-08-30T20:06:15.015598Z	2e60da8	PR opened

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