Fixes#710
A number property like "Year: 2026" rendered as "0.0.7.234" in the
note list column because the WHATWG URL parser canonicalizes integer-only
hosts to IPv4 form: new URL('https://2026').hostname === '0.0.7.234'.
formatChipLabel called isUrlValue('2026'), which returned true via the
bare-domain branch of normalizeExternalUrl, and then asked the URL parser
for the hostname.
Add a single guard in normalizeExternalUrl: when the input contains no '.',
reject it before the bare-domain candidate is constructed. The
parseHttpUrl(trimmed) branch above already handles inputs with an explicit
scheme (https://...), so the guard only narrows the bare-domain path -
the path that produced the bug. Existing cases ('example.com', 'localhost')
remain unaffected.
Two new vitest cases cover the regression ('2026' and '0') plus a parity
case for https://example.com to make sure the scheme branch is untouched.
