docs: 시스템 아키텍처 및 명령어 문서 추가

- COMMAND.md: 다양한 명령어와 설명 추가
- .claude/commands/design/1-system-architecture: 시스템 아키텍처 관련 문서 삭제
- .claude/commands/sc: 코드 분석, 빌드, 클린업, 설계, 문서화, 추정, 설명, Git 작업, 구현, 개선, 테스트, 문제 해결, 워크플로우 생성 등 다양한 명령어 문서 추가

.claude/commands/sc/design.md

@@ -0,0 +1,33 @@
+---
+allowed-tools: [Read, Grep, Glob, Write, Edit, TodoWrite]
+description: "Design system architecture, APIs, and component interfaces"
+---
+
+# /sc:design - System and Component Design
+
+## Purpose
+Design system architecture, APIs, component interfaces, and technical specifications.
+
+## Usage
+```
+/sc:design [target] [--type architecture|api|component|database] [--format diagram|spec|code]
+```
+
+## Arguments
+- `target` - System, component, or feature to design
+- `--type` - Design type (architecture, api, component, database)
+- `--format` - Output format (diagram, spec, code)
+- `--iterative` - Enable iterative design refinement
+
+## Execution
+1. Analyze requirements and design constraints
+2. Create initial design concepts and alternatives
+3. Develop detailed design specifications
+4. Validate design against requirements and best practices
+5. Generate design documentation and implementation guides
+
+## Claude Code Integration
+- Uses Read for requirement analysis
+- Leverages Write for design documentation
+- Applies TodoWrite for design task tracking
+- Maintains consistency with architectural patterns