docs: update documentation for v5.0 release - "Less is More"

Major documentation updates reflecting v5.0 core philosophy:

**Version Updates:**
- Update all docs to v5.0.0
- Remove MCP code-index dependency references
- Emphasize simplified, dependency-free architecture

**Removed Features:**
- Remove /workflow:concept-clarify command (deprecated)
- Clean up all concept clarification workflow documentation

**Command Corrections:**
- Fix memory command names: /update-memory-* → /memory:update-*
- Clarify test workflow execution pattern (generate → execute)

**Dependency Clarifications:**
- Replace "MCP code-index" with "ripgrep/find" in memory:load
- Clarify MCP Chrome DevTools usage in UI design workflows
- Update ui-design:capture to show multi-tier fallback strategy

**Files Updated:**
- README_CN.md - v5.0 version badge and core improvements
- COMMAND_REFERENCE.md - Remove deprecated commands, update descriptions
- COMMAND_SPEC.md - v5.0 version, clarify implementations
- GETTING_STARTED.md - v5.0 features, fix command names
- GETTING_STARTED_CN.md - v5.0 features (Chinese), fix command names
- INSTALL_CN.md - v5.0 simplified installation notes

🎯 Core Philosophy: Simplify dependencies, focus on core features,
improve stability with standard tools.

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

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

INSTALL_CN.md

@@ -4,6 +4,8 @@
 
 Claude Code Agent 工作流协调和分布式内存系统的交互式安装指南。
 
+> **版本 5.0：精简化安装** - 移除了外部 MCP 依赖，安装更简单、更稳定。使用标准工具（ripgrep/find）提供更好的性能和兼容性。
+
 ## ⚡ 一键远程安装（推荐）
 
 ### 所有平台 - 远程 PowerShell 安装