Dara saw hitching when dragging near walls and corners. Wall strokes are
drawn wider than the real wall, so an agent hugging one has its centre
inside the ink for a few frames at a time, and the cone was switched off
there, and again when the centre slipped just past the painted floor edge.
On the Garage-to-Garden drag on Haven that was one position in ten.

SvgHeightVisibility.standablePointNear pushes the origin out of every
blocking wall it lies in and onto the floor, by at most 2.5 SVG units, and
the cone widget stands the cone there. Kerbs and floor marks that do not
block a standing eye are not treated as walls. On the same path the cone
now never disappears; it moves at most a few tenths of a metre.

The timeline drive test renders into the real window now, which is the
only way the raster thread does real work in that harness.

Gate: all tests pass.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>