// Shared observable store: one state object, subscribe for changes, set() to
// patch. Views read state and re-render on notify. Nothing here touches the URL
// (the router owns navigable state) or the network (the api client owns that) —
// this is only the in-memory glue between them.
export function createStore(initial = {}) {
  let state = { ...initial };
  const listeners = new Set();

  function set(patch) {
    const next = typeof patch === "function" ? patch(state) : patch;
    state = { ...state, ...next };
    for (const listener of listeners) listener(state);
  }

  return {
    get: () => state,
    set,
    subscribe(listener) {
      listeners.add(listener);
      return () => listeners.delete(listener);
    },
  };
}