camera_from_view computed the camera target in f32 (view_target cast to
f32 before folding view_center), quantizing it to ~0.5 m at UTM scale.
Panning/zooming inside a floating viewport nudges view_target by sub-metre
f64 steps, so the camera snapped along the f32 grid and the drawn content
jittered — while the model view (f64 target) stayed smooth.
Compute the target in f64 (axis directions stay f32 — orientation only),
matching the model camera's precision.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>