Streamline config.json

[inverse]

Right now the way things are setup with config.json makes it hard to support both local and pre-built.

We should adopt what other extensions do like groccy.

Which as I understand is within config.json

• set version to dev for local builds
• Drop the image key to allow local builds

Figure out how those get patched on cI for releasing or if it's controlled via build-args

[inverse]

Previous attempt exposed dev to end users as an upgrade path.