[codex] Add auto-growing text inputs

[Matildevoldsen]

Summary

Adds first-class auto-growing multiline text input support for Native UI text inputs.

• adds a PHP autoGrow(int $minLines = 1, int $maxLines = 5) API and Blade auto-grow / autoGrow attribute support
• keeps the existing multiline, minLines, and maxLines behavior compatible
• wires the auto_grow prop through Android shared text input parsing and the chromeless BareTextInputRenderer
• wires the auto_grow prop through SwiftUI and asks vertical text fields to use intrinsic height with fixedSize(horizontal: false, vertical: true)
• moves text input behavior methods into a small concern so BaseTextInput.php stays under 300 lines

Why

Chat composer style inputs need to grow naturally from one line up to a capped number of lines without each app estimating wrapped line counts in Blade/PHP. Native UI already has multiline inputs; this adds the explicit API and native hints needed for textarea-style auto-growth.

Validation

Passed:

vendor/bin/pest tests/TextInputAutoGrowTest.php --colors=never
php -l src/Elements/BaseTextInput.php
php -l src/Elements/Concerns/ConfiguresTextInputBehavior.php
php -l tests/TextInputAutoGrowTest.php
git diff --check

Current upstream/fresh-clone test blockers, unrelated to this change:

vendor/bin/pest --colors=never
# Fails before project tests run because Native\Mobile\Icon\IosSymbol is missing from the installable nativephp/mobile dependency.

vendor/bin/pest tests/PluginTest.php tests/TextInputAutoGrowTest.php --colors=never
# PluginTest fails because it checks resources/ios/ButtonRenderer.swift, while upstream currently has resources/ios/NativeUIButtonRenderer.swift.