fix: write the prompt to STDOUT before readline() on Windows

[michalsn]

Description
This PR is a follow-up to #10507. On Windows readline_info() never exposes a library_version key: php-src adds it under #ifndef PHP_WIN32 (ext/readline/readline.c), because the extension is built on WinEditLine there instead of GNU readline. readline_info('library_version') therefore returns null on every Windows build with the extension enabled, and under declare(strict_types=1) the new str_contains() call in InputOutput::input() throws:

[TypeError]
str_contains(): Argument #1 ($haystack) must be of type string, null given
at SYSTEMPATH\CLI\InputOutput.php:48

Every spark command that asks a question (e.g. shield:setup, or any generator asked to overwrite a file) crashes on Windows since #10507, whenever the readline extension is enabled (the default in the official builds). Windows with readline disabled is not affected, as input() takes the fgets() path. Reproduced with the official PHP 8.4.25 and 8.0.25 builds.

A plain null guard is not enough: WinEditLine prints ANSI sequences passed in the readline prompt literally, so a coloured default option would render as [[32my[0m, n]:. This PR extracts the prompt decision into InputOutput::readlinePrompt():

• GNU readline (reports a version such as 8.2) gets the prompt with ANSI sequences wrapped in the non-printing markers, as in fix: pass prompt text to readline in CLI::prompt() so backspace does not erase it #10507.
• libedit (reports EditLine wrapper) gets the raw prompt, as in fix: pass prompt text to readline in CLI::prompt() so backspace does not erase it #10507.
• WinEditLine (reports no version) gets no prompt: the prompt is written to STDOUT first and readline() only reads the line, i.e. the pre-fix: pass prompt text to readline in CLI::prompt() so backspace does not erase it #10507 behaviour.

Tested interactively on Windows 11 / PHP 8.4.25 with CLI::prompt(), CLI::promptByKey() and a plain prompt: colours render correctly, the typed values come back, and the prompt text stays intact after backspacing past the start of the input (WinEditLine is not affected by the bug #10507 fixed, so the old behaviour is safe there).

Checklist:

• Securely signed commits
• Component(s) with PHPDoc blocks, only if necessary or adds value (without duplication)
• Unit testing, with >80% coverage
• User guide updated
• Conforms to style guide