[codex] Improve Studio rendering and export stability

[Mijiang111]

Summary

• Improve Studio/PPTX export stability across text, shapes, charts, tables, and generated export frames.
• Add richer chart/table export handling, hidden placeholder filtering, rotated text support, and more robust HTML report rendering paths.
• Include the current animation artifact and related Studio engine/rendering updates from the working tree.

Validation

• git diff --cached --check
• corepack pnpm typecheck