adding-new-islands

How to add a new built-in island to the OpenIslands monorepo end to end — first the interface/API design discipline and the .describe() copy conventions (the island is authored by an agent reading the schema, so the interface IS the product), then the exact file-by-file wiring: the schema registration points, the compiler binding-check, the runtime renderer + registry, the CLI skeleton, tests, and which docs are generated vs hand-edited. Use when adding, designing, reviewing, or naming a new island/chart/visual-block type, or when answering "how do I add an island to OpenIslands". The canonical worked example is the divergence.bars island.