docs: rename general-purpose agent to universal-executor and update documentation

Major updates in this release:

1. Agent Renaming (13 files, 21 references):
   - Renamed general-purpose → universal-executor to avoid naming conflicts
   - Updated all references in commands and workflows
   - Maintained backward compatibility in documentation

2. README Updates (4 files):
   - Removed /workflow:session:start step (auto-created by /workflow:plan)
   - Simplified workflow from 4 steps to 3 steps
   - Updated version to v4.6.2
   - Added CLI tool usage guidelines

3. GETTING_STARTED Enhancements (2 files):
   - Added Design Philosophy section explaining multi-model CLI integration
   - Added comprehensive CLI tool usage guide with common workflows
   - Reorganized quick start to emphasize automatic session creation
   - Added examples for bug fixes and feature development

Files modified:
- Agent config: .claude/agents/general-purpose.md
- Commands: 7 files in .claude/commands/
- Workflows: 5 files in .claude/workflows/
- Documentation: README.md, README_CN.md, GETTING_STARTED.md, GETTING_STARTED_CN.md

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

GETTING_STARTED_CN.md

@@ -3,6 +3,8 @@
 
 欢迎来到 Claude Code Workflow (CCW) v4.6.2！本指南将帮助您在 5 分钟内快速入门，体验由 AI 驱动的自动化软件开发流程，以及我们最新的工作流系统优化。
 
+**项目地址**：[catlog22/Claude-Code-Workflow](https://github.com/catlog22/Claude-Code-Workflow)
+
 ---
 
 ## ⏱️ 5 分钟快速入门