feat: add declarative Director feature actions

src/director/interactions/session.js

@@ -0,0 +1,61 @@
+/** Own one user-triggered action at a time; cancellation settles even an uncooperative adapter. */
+export function createInteractionSession({ execute, changed = () => {} }) {
+  let controller,
+    active = false,
+    busy = false,
+    selected = null;
+  let actions = new Map();
+  const state = () => ({ active, busy, selected, count: actions.size });
+  function clear() {
+    active = false;
+    busy = false;
+    selected = null;
+    actions.clear();
+    controller?.abort();
+    controller = null;
+    changed(state());
+  }
+  return {
+    clear,
+    getState: state,
+    activate(items) {
+      clear();
+      actions = new Map(items.map((item) => [item.id, item]));
+      active = !!actions.size;
+      changed(state());
+    },
+    async dispatch(id) {
+      const item = actions.get(id);
+      if (!active || busy || !item) return false;
+      const current = new AbortController();
+      controller = current;
+      busy = true;
+      selected = id;
+      changed(state());
+      let abort;
+      try {
+        const cancelled = new Promise((resolve) => {
+          abort = () => resolve(false);
+          current.signal.addEventListener('abort', abort, { once: true });
+        });
+        const work = Promise.resolve().then(() => {
+          if (current.signal.aborted) return false;
+          return execute(item, current.signal);
+        });
+        return (
+          (await Promise.race([work, cancelled])) !== false &&
+          !current.signal.aborted
+        );
+      } catch {
+        return false;
+      } finally {
+        current.signal.removeEventListener('abort', abort);
+        if (controller === current) {
+          busy = false;
+          controller = null;
+          changed(state());
+        }
+      }
+    },
+  };
+}