fix(text): Apply kerning to fix glyph overlap

[google-labs-jules]

This commit fixes a glyph overlapping issue by applying kerning during text rendering. The computeGlyphRunFromText function in src/pdf/renderers/text-renderer.ts was modified to account for kerning adjustments between glyph pairs. The logic now correctly handles surrogate pairs in Unicode strings, ensuring that kerning is applied properly and preventing rendering issues.

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PR created automatically by Jules for task 15116203077267198730 started by @celsowm

[google-labs-jules]

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