[HexCodeYT]

What changed

• Recognizes full http:// and https:// URLs, schemeless host/path links, and protocol-relative //host/path links.
• Preserves the input form instead of adding a scheme.
• Uses the recognized host for the same global and domain-specific cleaning rules used by full URLs.
• Rejects ambiguous ordinary text, email-like strings, relative paths, whitespace-containing input, and unsupported schemes.
• Preserves support for schemeful single-label hosts such as intranet URLs.
• Adds unit and fixture coverage for the reported youtu.be/... failure.

Root cause

clean_url had a hard gate that accepted only strings beginning with http:// or https://. Clipboard and CLI callers both use this function, so every otherwise-valid copied link without a scheme was returned unchanged before rule matching.

Verification

The exact reported command now returns:

youtu.be/LYa_ReqRlcs

Also verified schemeless YouTube, generic global tracking, protocol-relative links, ambiguous non-URLs, and schemeful intranet URLs.

• cargo fmt --check
• cargo test — 19 unit tests plus fixture/integration suites pass
• cargo clippy --all-targets -- -D warnings
• native app smoke test and Preview 3 package/checksum verification