Fix geometry clip bounds for infinite rectangles

[varphone]

This fixes the geometry example rendering issue on native Linux by preserving infinite clip bounds through the transformation and mesh preparation pipeline.

What changed:

• Keep Rectangle::INFINITE unchanged when applying a transformation.
• Skip snap/translation logic for infinite mesh clip bounds in iced_wgpu.

Why:

• The geometry example uses an infinite clip region for its custom mesh.
• Previously, the clip bounds could become NaN during transformation/snap calculation, which caused the mesh to be clipped away and the window to appear blank.

Validation:

• cargo check -p geometry passes
• cargo r -p geometry now produces finite clip bounds and renders through wgpu