feat(blueprint): refactor BlueprintComponent as proper ECS Component (#433)

* feat(blueprint): refactor BlueprintComponent as proper ECS Component

- Convert BlueprintComponent from interface to actual ECS Component class
- Add ready-to-use BlueprintSystem that extends EntitySystem
- Remove deprecated legacy APIs (createBlueprintSystem, etc.)
- Update all blueprint documentation (Chinese & English)
- Simplify user API: just add BlueprintSystem and BlueprintComponent

BREAKING CHANGE: BlueprintComponent is now a class extending Component,
not an interface. Use `new BlueprintComponent()` instead of
`createBlueprintComponentData()`.

* chore(blueprint): add changeset for ECS component refactor

* fix(node-editor): fix connections not rendering when node is collapsed

- getPinPosition now returns node header position when pin element is not found
- Added collapsedNodesKey to force re-render connections after collapse/expand
- Input pins connect to left side, output pins to right side of collapsed nodes

* chore(node-editor): add changeset for collapse connection fix

* feat(blueprint): add Add Component nodes for entity-component creation

- Add type-specific Add_ComponentName nodes via ComponentNodeGenerator
- Add generic ECS_AddComponent node for dynamic component creation
- Add ExecutionContext.getComponentClass() for component lookup
- Add registerComponentClass() helper for manual component registration
- Each Add node supports initial property values from @BlueprintProperty

* docs: update changeset with Add Component feature

* feat(blueprint): improve event nodes with Self output and auto-create BeginPlay

- Event Begin Play now outputs Self entity
- Event Tick now outputs Self entity + Delta Seconds
- Event End Play now outputs Self entity
- createEmptyBlueprint() now includes Event Begin Play by default
- Added menuPath to all event nodes for better organization

packages/framework/blueprint/src/index.ts

@@ -75,8 +75,29 @@ export { NodeRegistry, RegisterNode } from './runtime/NodeRegistry';
 export { BlueprintVM } from './runtime/BlueprintVM';
 export { BlueprintComponent } from './runtime/BlueprintComponent';
 export { BlueprintSystem } from './runtime/BlueprintSystem';
+export { ExecutionContext } from './runtime/ExecutionContext';
 export { createEmptyBlueprint, validateBlueprintAsset } from './types/blueprint';
 
+// Component registration helper
+import { ExecutionContext } from './runtime/ExecutionContext';
+import type { Component } from '@esengine/ecs-framework';
+
+/**
+ * @zh 注册组件类以支持在蓝图中动态创建
+ * @en Register a component class for dynamic creation in blueprints
+ *
+ * @example
+ * ```typescript
+ * import { registerComponentClass } from '@esengine/blueprint';
+ * import { MyComponent } from './MyComponent';
+ *
+ * registerComponentClass('MyComponent', MyComponent);
+ * ```
+ */
+export function registerComponentClass(typeName: string, componentClass: new () => Component): void {
+    ExecutionContext.registerComponentClass(typeName, componentClass);
+}
+
 // Re-export registry for convenience
 export {
     BlueprintExpose,