fix(text): honor parent render ordering

[thejustinwalsh]

Summary

• Make framework-neutral Text a composite Object3D so caller-owned parent Group ordering remains the primary Three.js sort key.
• Propagate Text.renderOrder as the secondary base across cold publication and retained Bitmap, MTSDF, Slug, and third-party raster updates.
• Require neutral Object3D raster roots and reject plugin Groups that would reset inherited group order.
• Keep nested React Text as source/span composition while preserving the standard Object3D prop surface.

Public contract

A parent Group supplies groupOrder. Text.renderOrder supplies the paragraph base, and each drawable retains its raster-local run offset. RasterObjectDrawBatch now exposes the synchronous, infallible setRenderOrderBase method so external raster packages can implement the same lifecycle without core internals.

Verification

• mise exec -- pnpm check
• mise exec -- pnpm scripts run benchmark:external-raster
  • WebGPU: 2/2 deterministic external raster frames
  • WebGL2: 2/2 deterministic external raster frames
  • The framebuffer proof resets Text.renderOrder to zero and therefore fails if Text or its plugin batch overrides the caller-owned parent Group.
• 33 focused Text, React, and retained-raster tests pass.
• The third-party raster package passes build, tests, typecheck, lint, and format.
• OKF validation reports zero errors and zero warnings; affected source digests were regenerated.
• Generated package-size evidence and reviewed ceilings pass.
• React Doctor v0.9.4 changed-scope score: 92/100. Its one warning points to the unchanged persistent-host provider, whose value is retained by the configured React Compiler and is already documented inline as a rule false positive.