fix(textkit): preserve run attributes during bidi reordering

[matangot]

Summary

Fixes #2900

The bidiReordering implementation shuffled individual glyphs across run boundaries using character-level index remapping (getItemAtIndex). This caused run attributes (color, font-weight, font-style, links, etc.) to be lost when rendering RTL text with nested styled <Text> elements.

Before (broken):

<Text style={{ direction: 'rtl' }}>
  עברית <Text style={{ color: 'red' }}>קשה</Text> שפה
</Text>

Glyphs from the red-styled run were remapped into the default-styled run, losing the red color. Bold, italic, and links were similarly corrupted.

Root cause: reorderLine() used indices.slice(run.start, run.end) to get reordered character positions, then getItemAtIndex() fetched glyphs from other runs at those positions. The fetched glyphs were placed back into the current run — stripping the original run's attributes.

Fix: Replace character-level glyph shuffling with run-level reordering:

1. Apply UAX Add meta-data to document #9 L2 algorithm at the run level to determine visual run order
2. Reverse glyphs/positions within RTL runs (odd bidiLevel)
3. Glyphs never cross run boundaries → all run attributes preserved

This also removes the bidi-js dependency from bidiReordering.ts (the bidi engine for computing embedding levels still uses it in engines/bidi.ts).

Test plan

• Existing 4 bidi tests pass unchanged
• New test: multi-run RTL preserves per-run color attribute after reordering
• New test: LTR embedded in RTL (level 2 in level 1) reorders correctly
• Full textkit test suite: 693 tests, 87 files, all passing

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[baderalrasheed]

Tested your fix and it resolved the issue for us in Arabic text renders.

Thanks for digging into this, a release including it would be very useful.