Fix v4 http_url schema

[hi-rai]

In Zod v4 mode, renderV4FormatCheck mapped validate:"http_url" to .check(z.httpUrl()).

z.httpUrl() is shorthand for z.url({ protocol: /^https?$/, hostname: z.regexes.domain }), and the hostname regex only accepts dotted, TLD-style domains. But go-playground/validator's http_url rule is url.Parse-based: it only requires an http/https scheme and a non-empty host. The generated Zod schema therefore rejects values the Go validator accepts:

Value	Go http_url	z.httpUrl()
https://localhost:8080/path	valid	rejected
http://127.0.0.1:9000/x	valid	rejected
https://intranet-host/browse/X	valid	rejected
https://example.com/a?b=c	valid	valid

The updated .check(z.url({ protocol: /^https?$/ })) now matches go-playground/validator's behavior