What?

Partially closes #234, #416

At a code-level, change the Image Generation Feature to be a stable Feature instead of an Experimental Feature.

Why?

The groundwork was laid in #316 to distinguish between an experimental Feature and a stable Feature. We left all Features as experimental but now want to promote certain ones that we feel have been thoroughly tested and bring significant value. We are starting with the Image Generation (which also includes Image Editing) Feature.

Note this only modifies things at the code-level, not the UI. Those changes are coming in #417. Worth noting that until that PR is merged, the Image Generation Feature will start to show in an existing "Other Features" section (from the current Editor Experiments section):

How?

• Move the Image_Generation class from the Experiments directory to the Features directory
• Mark this Feature as stable and remove the Experiment category of Editor
• Add a new features directory within our src directory and move all Image Generation JS code here
• Ensure this Feature is loaded properly and removed from loading as an Experiment
• Move all tests (E2E and unit) into a new Features directory and out of the Experiments directory for consistency
• Update docs

Use of AI Tools

None

Testing Instructions

1. Pull this PR down and run npm i && npm run build
2. Go to the settings page and ensure you no longer see Image Generation and Editing in the Editor Experiments section but you do see it in the Other Features section (again, this is temporary until Add visual-card presentation for featured experiments #417 is done)
3. Turn this Feature on and test it thoroughly, ensuring you have a Provider connected (like Google) that supports image generation and editing