v1.0.0 배포 준비: CHANGELOG, LICENSE, 프로젝트 메타 파일 추가

- CHANGELOG.md: Phase 1~13 + 랜딩 페이지 전체 변경 이력
- LICENSE: MIT
- CONTRIBUTING.md: 개발 환경, 코드 표준, PR 프로세스
- SECURITY.md: 보안 정책, 취약점 보고 절차
- .editorconfig: 에디터 설정 통일 (indent, charset, eol)
- .nvmrc: Node.js 20
- .gitattributes: line ending 정규화, 바이너리 선언, linguist 설정
- .gitignore: site/dist, Python, Whisper 모델 등 누락 항목 추가

CONTRIBUTING.md

@@ -0,0 +1,83 @@
+# Contributing to D3RO Voice
+
+Thank you for your interest in contributing to D3RO Voice!
+
+## Development Setup
+
+### Prerequisites
+- Node.js 20+
+- Python 3.10+ (for faster-whisper sidecar)
+- Ollama (for LLM features)
+- Windows 10/11 (primary platform)
+
+### Getting Started
+
+```bash
+# Clone the repository
+git clone https://gitlab.twentyoz.kr:8443/d3r0/voice.git
+cd voice
+
+# Install dependencies
+npm install
+
+# Download SoX binary (Windows)
+npm run setup:sox
+
+# Start development
+npm run dev
+```
+
+### Project Structure
+
+```
+src/
+  main/           # Electron main process (services, IPC, DB)
+  renderer/       # React app (MUI, components, pages)
+  preload/        # contextBridge IPC bridge
+  shared/         # Shared types, IPC channels, errors
+site/             # Landing page (Vite + React + Tailwind)
+docs/             # Design documents and phase specs
+tests/            # Unit tests (vitest)
+```
+
+### Code Standards
+
+- TypeScript strict mode (`noImplicitAny`, `strictNullChecks`)
+- No `any` types
+- No `console.log` (use electron-log via LoggerService)
+- Colors via `d3roPalette` CSS variables (no hardcoded hex in components)
+- UI strings via `t()` i18n function (no hardcoded Korean/English)
+- Services: singleton + EventEmitter pattern
+- IPC channels defined in `src/shared/ipc-channels.ts`
+
+### Running Tests
+
+```bash
+npm run typecheck    # Type checking
+npm run lint         # ESLint
+npm run test         # Unit tests
+```
+
+### Building
+
+```bash
+npm run build        # Production build
+npm run dist         # Build + NSIS installer
+```
+
+## Design Documents
+
+Before implementing, always reference:
+- `docs/design/00-master-architecture.md`
+- `docs/design/01-service-specifications.md`
+- `docs/design/02-ipc-and-types.md`
+- `docs/design/03-db-and-ui.md`
+
+## Pull Request Process
+
+1. Create a feature branch from `main`
+2. Follow the coding standards above
+3. Ensure `npm run typecheck` passes
+4. Ensure `npm run test` passes
+5. Update CHANGELOG.md if applicable
+6. Submit a merge request with a clear description