feat: add AI学习助手 agent (KG+RAG ideal) and renshenguo feishu bot

- Add AI学习助手 agent creation script with all 39 tools, 3-layer KG+RAG memory
- Add renshenguo (人参果) feishu bot integration (app_service + ws_handler)
- Register renshenguo WS client in main.py startup
- Add RENSHENGUO_APP_ID / RENSHENGUO_APP_SECRET / RENSHENGUO_AGENT_ID config
- Reorganize docs from root into docs/ subdirectories
- Move startup scripts to scripts/startup/
- Various backend optimizations and tool improvements

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

scripts/testing/test_output_variable_extraction.py

@@ -0,0 +1,66 @@
+#!/usr/bin/env python3
+"""
+测试output变量提取逻辑
+"""
+import sys
+sys.path.insert(0, 'backend')
+
+from app.services.workflow_engine import WorkflowEngine
+
+# 模拟llm-format节点的输入数据
+input_data = {
+    'right': {
+        'right': {
+            'right': '是的，我记得！根据我们之前的对话，你告诉我你的名字叫"老七"。我会在本次对话中记住这个名字，以便更好地为你提供帮助。如果你希望我用其他称呼，也可以随时告诉我。',
+            'query': '你还记得我的名字吗？'
+        },
+        'memory': {
+            'conversation_history': [],
+            'user_profile': {},
+            'context': {}
+        },
+        'query': '你还记得我的名字吗？'
+    },
+    'memory': {
+        'conversation_history': [],
+        'user_profile': {},
+        'context': {}
+    },
+    'query': '你还记得我的名字吗？'
+}
+
+# 创建WorkflowEngine实例
+engine = WorkflowEngine("test", {"nodes": [], "edges": []})
+
+# 测试_get_nested_value方法
+print("测试_get_nested_value方法:")
+value1 = engine._get_nested_value(input_data, 'output')
+print(f"  _get_nested_value(input_data, 'output'): {value1}")
+
+# 测试output变量提取逻辑
+print("\n测试output变量提取逻辑:")
+right_value = input_data.get('right')
+print(f"  right_value类型: {type(right_value)}")
+print(f"  right_value: {str(right_value)[:100]}")
+
+if right_value is not None:
+    if isinstance(right_value, str):
+        value = right_value
+        print(f"  ✅ 从right字段（字符串）提取: {value[:100]}")
+    elif isinstance(right_value, dict):
+        current = right_value
+        depth = 0
+        while isinstance(current, dict) and depth < 10:
+            if 'right' in current:
+                current = current['right']
+                depth += 1
+                if isinstance(current, str):
+                    value = current
+                    print(f"  ✅ 从right字段（嵌套{depth}层）提取: {value[:100]}")
+                    break
+            else:
+                break
+        else:
+            print(f"  ❌ 无法提取字符串值")
+
+print("\n测试完成")