Keep descenders of a text whole and frame it at its drawn size

A text was drawn into a texture as tall as Pixi measures the string
"|ÉqÅM". Whatever reached further, like the "g" of Manrope (0.015 em
below the "q"), was cut off at the bottom. The blue frame around a
text was only estimated from the font size and the number of letters,
so it was far too wide for most texts.

- textPicture.ts takes the height of a line from the font itself
  (fontBoundingBoxAscent and fontBoundingBoxDescent, as a browser
  does). Pixi draws with a margin, and the picture is cut to that box
  afterwards. Where Pixi's own box is larger, Pixi's box wins.
- Both raster paths (linear and nearest) use the cut.
- The height no longer depends on the letters typed, so a text does
  not jump while it is edited.
- bounds.ts asks a measurer that textPicture.ts registers
  (setTextMeasure). Selection, picking in a running game, framing the
  camera, the drop preview and culling all get the measured size.
  The footprint functions take the font file for this.
- Unit tests in node have no canvas and keep the estimate
  (estimatedTextSize).
- Texts get taller: Source Sans 3 at 48 px is 68 instead of 55 px,
  Manrope is 1.366 em instead of 1.25 em. The glyphs stay in place,
  the centre moves by less than half a pixel. A shader on a text
  gets a taller UV rectangle.

Tests:
- Gate on melektaus-atx green: 307 files, 4762 tests.
- 5 new unit tests for textBox, textCut and the measurer hook.
- e2e 30: 26 checks, 30f-iii new. The texture is 68 high, the font
  box is 68, the frame equals the drawn picture (237x68).
- Counter test: with Pixi's old box the texture is 55 high and
  30f-iii is red.
- Not checked in the browser: the Manrope caption of the user and
  texts with several lines.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

src/runtime/World.ts

@@ -19,10 +19,12 @@ import { descendantsBelow } from '../core/model/walk';
 import { isOverlayCamera } from '../core/model/renderLayers';
 import { findAsset, findAssetOf, findScene, type Project } from '../core/model/Project';
 import { createSceneObject, objectName, type SceneObject } from '../core/model/SceneObject';
+import { fontFileOf } from '../core/model/font';
 import { apply, IDENTITY } from '../core/model/matrix';
 import { hasTransformProps } from '../core/properties/PropertySchema';
 import { carriedTransform, localMatrixOf, transformOf } from '../core/properties/transform';
 import { footprintContains } from '../core/properties/bounds';
+import { fontOf } from '../core/properties/fonts';
 import { pointerThrough } from '../core/properties/camera';
 import { colliderFrame, colliderShape, shapeContains } from '../core/properties/collider';
 import { resolveSceneObjectProps } from '../core/properties/resolve';
@@ -606,7 +608,13 @@ export class World {
     return parts.some(
       (e) =>
         (e.type === 'sprite' || e.type === 'text') &&
-        footprintContains(e.type, e.props, worldMatrixOf(e), point),
+        footprintContains(
+          e.type,
+          e.props,
+          worldMatrixOf(e),
+          point,
+          fontFileOf(this.project, fontOf(e.props)),
+        ),
     );
   }