ext/uri: RFC 3986 IPv6 handling is inconsistent

Description

The following code:

<?php
$u = new Uri\Rfc3986\Uri("http://[::0:0A]/");
var_dump($u->getRawHost());
var_dump($u->getHost());
var_dump($u->toRawString());
var_dump($u->toString());

Resulted in this output:

string(8) "[::0:0A]"
string(8) "[::0:0a]"
string(49) "http://[0000:0000:0000:0000:0000:0000:0000:000a]/"
string(49) "http://[0000:0000:0000:0000:0000:0000:0000:000a]/"

But I expected this output instead:

string(8) "[::0:0A]"
string(8) "[0000:0000:0000:0000:0000:0000:0000:000a]"
string(49) "http://[::0:0A]/"
string(49) "http://[0000:0000:0000:0000:0000:0000:0000:000a]/"

Alternatively I might expect this output:

string(8) "[::0:0A]"
string(8) "[::a]"
string(49) "http://[::0:0A]/"
string(49) "http://[::a]/"

PHP Version

PHP 8.5.8 (cli) (built: Jul  1 2026 16:35:50) (NTS)
Copyright (c) The PHP Group
Zend Engine v4.5.8, Copyright (c) Zend Technologies
    with Zend OPcache v8.5.8, Copyright (c), by Zend Technologies

Operating System

Arch Linux

Start in ext/uri and reproduce the reported Uri Rfc3986 IPv6 example, comparing getRawHost(), getHost(), toRawString(), and toString(). Check the RFC 3986 handling and existing tests for IPv6 normalization; done means the chosen normalization behavior is consistent across these methods and covered by regression tests.