christabor/flask_jsondash ? reverse-engineered prompt

Build me a Flask based dashboard app that lets me create charts from JSON config only, with no custom frontend code. I want to point each widget at my own API endpoint, then render different chart types like line, timeseries, bar, and other common dashboard visualizations.

It should let me save and load dashboard layouts, drag and drop widgets around, and support a couple layout styles, like a normal grid and a more freeform setup. I also want basic edit controls so I can add a module, change its size, and edit the raw JSON when needed.

Please make it work as a reusable blueprint or app I can drop into an existing Flask project, and include a simple example app so I can see it running right away. If you need to check current docs for chart libraries or Flask patterns, look them up online.