The bindings under src/wit are generated from the pumpkin-plugin-wit
submodule by tools/gen.zig. The canonical ABI is handled at comptime in
src/abi.zig, so plugins are plain wasm32-freestanding modules and only
need wasm-tools to become a component.
On top of that there is a small hand written layer: plugin registration,
typed event handlers, declarative commands (cmd), text components from
struct literals (msg) and std.log support.
