feat(engine): add performAction dispatcher by kind

src/engine/game.ts

@@ -220,6 +220,50 @@ export function maybeStartLoopAction(state: GameState, content: Content): void {
   }
 }
 
+/**
+ * Single entry point for all player-initiated action dispatch.
+ *
+ * Dispatches by action.kind to the appropriate per-kind function:
+ * - instant: execute immediately (costs/yields, no queue slot)
+ * - timed:   enqueue (start if idle, queue otherwise)
+ * - loop:    toggle player enable preference; start runner if just enabled
+ * - story:   resolve storyChoiceId and apply the choice
+ * - context: not implemented in M1 — throws
+ *
+ * Note on loop toggle: disabling is always allowed, even when the action is
+ * currently unaffordable. Affordability is the runner's concern (maybeStartLoopAction
+ * re-checks each tick). Throwing on unaffordable before toggling would wrongly
+ * block the player from DISABLING an active but now-unaffordable loop.
+ */
+export function performAction(state: GameState, content: GameContent, actionId: string): void {
+  const action = content.actionsById[actionId];
+  if (!action) throw new Error(`Unknown action "${actionId}"`);
+
+  switch (action.kind) {
+    case 'instant':
+      executeInstant(state, content, actionId);
+      break;
+    case 'timed':
+      enqueueAction(state, content, actionId);
+      break;
+    case 'loop': {
+      const willEnable = !state.enabledLoopActionIds[actionId];
+      state.enabledLoopActionIds[actionId] = willEnable;
+      if (willEnable) {
+        maybeStartLoopAction(state, content);
+      }
+      break;
+    }
+    case 'story':
+      executeStoryAction(state, content, actionId);
+      break;
+    case 'context':
+      throw new Error(`Context action "${actionId}" is not implemented`);
+    default:
+      throw new Error(`Unknown action kind "${(action as { kind: string }).kind}"`);
+  }
+}
+
 /**
  * Advance the active action by `tickMs`. On completion, grants yields and
  * advances the queue — actions do not auto-repeat when the queue is empty.