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/implement.md

@@ -0,0 +1,54 @@
+---
+allowed-tools: [Read, Write, Edit, MultiEdit, Bash, Glob, TodoWrite, Task]
+description: "Feature and code implementation with intelligent persona activation and MCP integration"
+---
+
+# /sc:implement - Feature Implementation
+
+## Purpose
+Implement features, components, and code functionality with intelligent expert activation and comprehensive development support.
+
+## Usage
+```
+/sc:implement [feature-description] [--type component|api|service|feature] [--framework react|vue|express|etc] [--safe]
+```
+
+## Arguments
+- `feature-description` - Description of what to implement
+- `--type` - Implementation type (component, api, service, feature, module)
+- `--framework` - Target framework or technology stack
+- `--safe` - Use conservative implementation approach
+- `--iterative` - Enable iterative development with validation steps
+- `--with-tests` - Include test implementation
+- `--documentation` - Generate documentation alongside implementation
+
+## Execution
+1. Analyze implementation requirements and detect technology context
+2. Auto-activate relevant personas (frontend, backend, security, etc.)
+3. Coordinate with MCP servers (Magic for UI, Context7 for patterns, Sequential for complex logic)
+4. Generate implementation code with best practices
+5. Apply security and quality validation
+6. Provide testing recommendations and next steps
+
+## Claude Code Integration
+- Uses Write/Edit/MultiEdit for code generation and modification
+- Leverages Read and Glob for codebase analysis and context understanding
+- Applies TodoWrite for implementation progress tracking
+- Integrates Task tool for complex multi-step implementations
+- Coordinates with MCP servers for specialized functionality
+- Auto-activates appropriate personas based on implementation type
+
+## Auto-Activation Patterns
+- **Frontend**: UI components, React/Vue/Angular development
+- **Backend**: APIs, services, database integration
+- **Security**: Authentication, authorization, data protection
+- **Architecture**: System design, module structure
+- **Performance**: Optimization, scalability considerations
+
+## Examples
+```
+/sc:implement user authentication system --type feature --with-tests
+/sc:implement dashboard component --type component --framework react
+/sc:implement REST API for user management --type api --safe
+/sc:implement payment processing service --type service --iterative
+```