[Akshats-git]

Resolves #9381

Changes:

In 2.x, createCanvas() returns a p5.Renderer and createGraphics() returns a p5.Graphics. Neither is a p5.Element anymore, so saveCanvas() did not recognise them. It treated the object as the filename and threw filename.includes is not a function. Nothing was saved.

This PR adds a check for p5.Renderer and p5.Graphics at the start of saveCanvas() and uses their .canvas. save() in src/io/files.js already does the same thing.

• src/image/image.js: handle p5.Renderer and p5.Graphics and add them to the @param type.
• docs/parameterData.json: same type update so FES accepts these arguments.
• test/unit/image/downloading.js: 4 new tests on a real sketch (2D canvas, canvas with a filename and extension, WEBGL canvas, p5.Graphics). The existing tests only used a mock and never passed a canvas which is why this was missed. The new tests fail without the fix.

All six examples on the saveCanvas() reference page now save a file in Chrome and Firefox, the same as in 1.11.10.

I used an AI assistant to help fix and write the tests. I have reviewed and tested every change myself.

PR Checklist

• npm run lint passes
• Inline reference is included / updated
• Unit tests are included / updated