Shaders draw in the sprite's own pass: a Mesh with the graph's fragment, no filter (#77)

A sprite's picture is now a Mesh (unit quad, sibling of its Graphics node, which keeps
only the hit area); a worn shader replaces Pixi's fragment in that draw, so there is no
intermediate texture and no extra render pass. Measured on the HD 630: 400 shaded
sprites hold 60 fps (was 34), 800 hold 56 (was 20).

Two Pixi facts the code leans on: a mesh's texture is bound only for Pixi's own shader,
so GraphShader.wear hands it over; and MeshPipe caches whether a mesh batches and
re-checks it only in a frame without structure changes, so switching a shader on or
off calls mesh.unload().

The console panel mirrors console.group/groupCollapsed/groupEnd and fills the %s %d
%o %c directives, so Pixi's deprecation warning shows its head, not only its stack.
E2E 12 guards against the addChild-on-Graphics warning, 28 counts shaders instead of
filters.

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

tools/seed-actor.mjs

@@ -238,7 +238,7 @@ const project = {
       frames,
     },
     ...walkAnimations,
-    // Present but worn by nothing: the smoke reads the actor's pixels, a filter pass must not touch them.
+    // Present but worn by nothing: the smoke reads the actor's pixels, a shader must not touch them.
     adjustColorsShader(),
     {
       id: 'actor-sprite',