Fix Vello renderer cropping wide miter joins and square caps

[Keavon]

This bug occurs in Vello when a non-default alpha blending setting is used like an opacity <100%. The render bounds given to Vello was given with an incorrectly too-small worst-case area.

Vello (before):

SVG (unchanged) and Vello (after):

[cubic-dev-ai]

No issues found across 2 files

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 introduces a new method max_aabb_inflation to the Stroke struct in vector-types, which calculates a worst-case upper bound for stroke extent by accounting for miter joins and square caps. The renderer in rendering has been updated to use this new method instead of effective_width when determining bounding box inflation, ensuring that compositing layers do not crop stroke geometry. I have no feedback to provide as there were no review comments to evaluate.

[gemini-code-assist]

Code Review

This pull request introduces a max_aabb_inflation method to the Stroke struct, providing a more accurate worst-case upper bound for stroke extent by accounting for miter joins and square caps. This new method replaces the use of effective_width in the renderer to ensure better clipping bounds. Feedback includes a correction for a double-scaling issue in the inflation calculation and a suggestion to rename a variable for consistency.