refactor: rename platform from 低代码智能体平台 to 天工智能体平台

The platform has evolved from a low-code workflow engine to an autonomous
agent platform with ReAct runtime, multi-agent marketplace, persistent
memory, multimodal tools, and multi-channel integration.

"天工" (Tiangong) draws from 《天工开物》- the wonders of nature and human
ingenuity, reflecting the platform's purpose: empowering users to create
and orchestrate AI agents as masterfully as nature creates all things.

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

scripts/startup/start.sh

@@ -1,8 +1,8 @@
 #!/bin/bash
 
-# 低代码智能体平台启动脚本
+# 天工智能体平台启动脚本
 
-echo "🚀 启动低代码智能体平台..."
+echo "🚀 启动天工智能体平台..."
 echo ""
 
 # 检查Docker是否运行