feat(fsm): 添加有限状态机模块 (#327)

- 添加 IStateMachine 接口，支持泛型状态和上下文
- 添加 StateMachine 实现
- 支持状态定义 (onEnter/onExit/onUpdate)
- 支持转换定义和条件
- 支持事件监听 (onChange/onEnter/onExit)
- 添加 8 个蓝图节点:
  - GetCurrentState, TransitionTo, CanTransition
  - IsInState, WasInState, GetStateDuration
  - EvaluateTransitions, ResetStateMachine

packages/fsm/module.json

@@ -0,0 +1,23 @@
+{
+    "id": "fsm",
+    "name": "@esengine/fsm",
+    "globalKey": "fsm",
+    "displayName": "State Machine",
+    "description": "有限状态机 | Finite State Machine",
+    "version": "1.0.0",
+    "category": "AI",
+    "icon": "GitBranch",
+    "tags": ["fsm", "state", "machine", "ai"],
+    "isCore": false,
+    "defaultEnabled": true,
+    "isEngineModule": true,
+    "canContainContent": false,
+    "platforms": ["web", "desktop"],
+    "dependencies": ["core"],
+    "exports": {
+        "components": ["StateMachineComponent"],
+        "systems": []
+    },
+    "outputPath": "dist/index.js",
+    "pluginExport": "FSMPlugin"
+}