Transform: scale, rotation and mirror as properties, world transform as a matrix chain, oriented colliders (#76)

Four new rows on sprite, text, collider and container (block TRANSFORM):
scale, rotation in degrees clockwise, mirrorX, mirrorY. As properties they
get override/reset/apply, loading of old projects, write-back after play and
the Properties node for free; camera and behavior have none.

The hierarchy composes T*R*S per level (composeAlongChain replaces
sumAlongChain), so children rotate and scale with their parent. Reparenting
and grouping keep the look (carriedTransform). Drawing goes through
placeNode, the gizmo is a polygon, cull and objectRect use the AABB, drags
are computed in the parent's system.

Colliders are oriented boxes: SAT for box/box, box-circle in the box frame;
exitDistance replaces axisSeparation/axisCorrection, moveAndSlide moves along
the object's own axes.

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

src/editor/debugHook.ts

@@ -187,6 +187,8 @@ export function installDebugHook(app: Application, state: EditorState, editor: E
     shownLabel,
     tabBounds: () => editor.tabBounds(),
     viewportCenter: () => centreOf(viewport),
+    /** Pans the Scene tab to a world point – a step's own lane, away from what earlier steps left. */
+    lookAt: (x: number, y: number) => viewport.lookAt(x, y),
     /** Its drawn box – a step that wants an empty spot must stay inside what the console left over. */
     viewportRect: () => {
       const p = viewport.getGlobalPosition();