canva: AI-optimize MCP action set

Canva today can create a design, kick off an import, export a design, list designs, and upload an asset. That's a start, but an agent can't do much with a design once it exists. We'd like these improved and new tools added so an agent can manage designs and assets more fully, and so each tool is easy for an agent to reach for and get right.

A few things an agent can't do today, for example:
- Open a specific design and read its details
- Find designs by name or folder, not just list them
- Duplicate a design or apply a brand template
- Organize folders and assets
- Check the status of an import or export job

**API reference:** https://www.canva.dev/docs/connect/

**Add marker:**
When a component is AI-optimized, add this as the first line of the file:
```
// x-pd-ai: optimized
```
Add it to each action file and to the app's `.mjs` file.