RFD 1054: The planner inside the studio core
Problem
extension/ ran Elixir in an editor panel, through Popcorn and AtomVM. It proved the pipeline, and it could not ship.
AtomVM needs SharedArrayBuffer, thus the page must be cross-origin isolated. An editor webview is not isolated, and an extension cannot set the headers. The panel worked only with codium --enable-coi.
The proof stands, and the vehicle does not.
Decision
Delete extension/. Put the planner inside weftspun_studio, which RFD 1019 already makes the API server.
RFD 1023 gives the shape, and this RFD does not restate it.
See DETAILS.md for the wrong-answer record of a second application and the port-mocking rule. It also gives the measured plans, three taskweft fixes this work needed, and the two planner routes.