feat(ios): add textAlignment

[kacperzolkiewski]

Summary

This PR:

1. Adds textAlignment support on iOS
2. Applies a minimal NSKernAttributeName to zero-width spaces (\u200B).

• ZWS has zero advance width, NSLayoutManager produces a zero-width usedRect for ZWS-only lines, which under right/center alignment collapses the line height. The minimal kerning gives the glyph a non-zero advance, preserving line geometry while remaining invisible.

Test Plan

Run example app and play with textAlignment when different styles are toggled.
Check if paragraphs/lists with different textAlignment than left are properly parsed and contain style="text-align:center|right|justify" inside HTML

Screenshots / Videos

Screen.Recording.2026-03-11.at.11.05.29.mov

Compatibility

OS	Implemented
iOS	✅
Android	❌

[MartycFly321]

@kacperzolkiewski Awesome feature! Would love to see it implemented.
I remember from the foreground color PR that it only gets approved if it works for IOS AND Android:

#266 (comment)
"Hey @IvanIhnatsiuk, it's super nice to get such verbose contribution from the community! While the feature is potentially interesting for us we cannot really proceed with it for now; we want the API and new features to be working on both mobile platforms from the get-go. Either way, great work!"