Remove gaps between text glyph bounding box click targets so selection is more reliable

[Keavon]

An improvement to #4095.

Each glyph's box is widened to touch the adjacent glyph, instead of just tightly bounding its own geometry:

[cubic-dev-ai]

No issues found across 1 file

Confidence score: 5/5

• Automated review surfaced no issues in the provided summaries.
• No files require special attention.

[gemini-code-assist]

Code Review

This pull request implements a mechanism to widen glyph bounding boxes horizontally, filling gaps between adjacent characters to improve click-targeting for text. This is achieved by deferring click target creation to the finalize stage and introducing a widen_horizontal_gaps helper function. Review feedback suggests optimizing memory usage by storing bounding boxes directly instead of full subpaths and increasing the floating-point tolerance when comparing baselines to ensure more robust layout calculations.