Improve menu bar icon crispness at small sizes

[ryota-kishimoto]

Problem

The menu bar icon (18x18 / 36x36) appears blurry/fuzzy due to the complex bezier curves in the SVG generated by vtracer.

Investigation

• The original gitpeek-menubar.svg contains thousands of bezier curve coordinates
• At 18px/36px, these complex paths produce anti-aliasing artifacts that look "fuzzy"
• ImageMagick's SVG renderer doesn't properly handle stroke-width
• rsvg-convert renders strokes correctly but the bezier complexity is the root cause
• Geometric SVG (circles + lines) renders crisp but changes the design feel

Possible approaches

• Hand-craft a pixel-hinted SVG optimized for 18px display
• Use SF Symbols (e.g. arrow.triangle.branch) for pixel-perfect rendering
• Create pixel art PNG directly at 18x18 and 36x36
• Simplify the original SVG paths while keeping the same visual design

Notes

• rsvg-convert (librsvg) gives better results than ImageMagick for SVG→PNG
• macOS menu bar icons use isTemplate = true so only shape matters (auto light/dark)