feat(plugins): consolidate official plugins with independent releases (LANG-180) (#2797)

Co-authored-by: multica-agent <[email protected]>

plugins/KnowledgeEngine/LangRAG/components/knowledge_engine/__init__.py

@@ -0,0 +1,17 @@
+"""Knowledge engine package exports.
+
+Keep the LangRAG import lazy so importing helper modules such as
+``components.knowledge_engine.query_rewrite`` does not require optional parser
+dependencies.
+"""
+
+
+def __getattr__(name: str):
+    if name == "LangRAG":
+        from .langrag import LangRAG
+
+        return LangRAG
+    raise AttributeError(name)
+
+
+__all__ = ["LangRAG"]