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/git.md

@@ -0,0 +1,34 @@
+---
+allowed-tools: [Bash, Read, Glob, TodoWrite, Edit]
+description: "Git operations with intelligent commit messages and branch management"
+---
+
+# /sc:git - Git Operations
+
+## Purpose
+Execute Git operations with intelligent commit messages, branch management, and workflow optimization.
+
+## Usage
+```
+/sc:git [operation] [args] [--smart-commit] [--branch-strategy]
+```
+
+## Arguments
+- `operation` - Git operation (add, commit, push, pull, merge, branch, status)
+- `args` - Operation-specific arguments
+- `--smart-commit` - Generate intelligent commit messages
+- `--branch-strategy` - Apply branch naming conventions
+- `--interactive` - Interactive mode for complex operations
+
+## Execution
+1. Analyze current Git state and repository context
+2. Execute requested Git operations with validation
+3. Apply intelligent commit message generation
+4. Handle merge conflicts and branch management
+5. Provide clear feedback and next steps
+
+## Claude Code Integration
+- Uses Bash for Git command execution
+- Leverages Read for repository analysis
+- Applies TodoWrite for operation tracking
+- Maintains Git best practices and conventions