Add `aabb: [f32; 4]` field to WireModel (world-space 2-D bounding box).
In tessellate_entity() set each wire's AABB from e.as_entity().bounding_box()
via new entity_aabb() helper; Insert sub-entities each get their own AABB.
Preview/interim wires and any entity returning a zero-extent default box get
UNBOUNDED_AABB so they are never pre-rejected.
Replace the chord-sphere heuristic in Snapper::wire_in_range() with a proper
AABB vs snap-circle overlap test. The new check is four scalar comparisons and
correctly handles closed curves (circles, arcs) which the chord-sphere approach
had to special-case.
Co-Authored-By: Claude Sonnet 4.6 <[email protected]>
DIMALIGNED: 3-click flow (p1 → p2 → dim line position) → DimensionAligned.
Rubber-band preview shows extension lines and dim line offset.
DIMDIAMETER: 3-click flow (center → arc point → text position) → DimensionDiameter.
Previews the diameter chord line.
Co-Authored-By: Claude Sonnet 4.6 <[email protected]>
