[DRAFT] feat: canvas state export/import via Base64

[davidsoncabista]

Overview

This is a work-in-progress PR to implement canvas state export/import functionality.
I'm opening this as a Draft to share the proposed architecture and core utilities.

Changes

• Architecture Doc: Created docs/CANVAS_EXPORT_BASE64_ARCHITECTURE.md outlining the serialization process.
• Utility Functions: Created frontend/src/utils/exportCanvas.ts with:
  • exportCanvasToBase64: Handles Unicode-safe serialization.
  • importCanvasFromBase64: Handles decoding and type-safe restoration.
  • SSR Support: Included globalThis fallback for environments where Buffer or btoa might vary.

What's done:

• Architecture specification (docs/CANVAS_EXPORT_BASE64_ARCHITECTURE.md).
• Core utility functions with Unicode and SSR support (frontend/src/utils/exportCanvas.ts).

To-do:

• Add unit tests for the utilities.
• Implement Export/Import UI components.

Feel free to comment on the architecture/serialization logic!

@Pouzor, this is a foundational step for the portable canvas feature. Feedback on the schema versioning is welcome!