v1.13.1 — scene controls, smooth geometry curves, verbatim labels

v1.13.1 — VisualWeaver

A 3-D scene you can actually turn — now with controls under the canvas — and a
geometry patch: smooth curves, verbatim labels and SVG-style dashes.

3-D scenes: interaction restored, controls added

In 1.13.0 a 3-D scene could not be rotated, zoomed or panned: the "3-D view
paused" overlay meant for a lost WebGL context was painted over every live scene
and took each drag and wheel. It now appears only when the context is actually
lost.

Every scene card also gains a control strip under the canvas: Rotate,
Tilt and Zoom sliders that show the current view and drive it — with the
keyboard, a finger, or for a precise angle — and follow a mouse orbit so the two
never disagree, plus ↻ Spin, which turns the scene continuously until you
touch it.

Smooth curves in geometry

New element types bezier / curve draw a cubic Bézier through their
control points, and spline draws a curve that passes through every point —
for light paths, trajectories and freehand shapes.

Fixes

• A geometry text label is drawn exactly as written: R_s and x^2 stay R_s
  and x^2 instead of appearing as the literal strings R<sub>s</sub> and
  x<sup>2</sup>.
• A geometry stroke set the SVG way — "dashArray": "5,5" — is now dashed
  instead of drawn solid.