🎉 Initial commit: Document Server MVP

✨ Features implemented:
- FastAPI backend with JWT authentication
- PostgreSQL database with async SQLAlchemy
- HTML document viewer with smart highlighting
- Note system connected to highlights (1:1 relationship)
- Bookmark system for quick navigation
- Integrated search (documents + notes)
- Tag system for document organization
- Docker containerization with Nginx

🔧 Technical stack:
- Backend: FastAPI + PostgreSQL + Redis
- Frontend: Alpine.js + Tailwind CSS
- Authentication: JWT tokens
- File handling: HTML + PDF support
- Search: Full-text search with relevance scoring

📋 Core functionality:
- Text selection → Highlight creation
- Highlight → Note attachment
- Note management with search/filtering
- Bookmark creation at scroll positions
- Document upload with metadata
- User management (admin creates accounts)

backend/src/models/highlight.py

@@ -0,0 +1,47 @@
+"""
+하이라이트 모델
+"""
+from sqlalchemy import Column, String, DateTime, Text, Integer, ForeignKey
+from sqlalchemy.dialects.postgresql import UUID
+from sqlalchemy.orm import relationship
+from sqlalchemy.sql import func
+import uuid
+
+from src.core.database import Base
+
+
+class Highlight(Base):
+    """하이라이트 테이블"""
+    __tablename__ = "highlights"
+
+    id = Column(UUID(as_uuid=True), primary_key=True, default=uuid.uuid4)
+    
+    # 연결 정보
+    user_id = Column(UUID(as_uuid=True), ForeignKey("users.id"), nullable=False)
+    document_id = Column(UUID(as_uuid=True), ForeignKey("documents.id"), nullable=False)
+    
+    # 텍스트 위치 정보
+    start_offset = Column(Integer, nullable=False)  # 시작 위치
+    end_offset = Column(Integer, nullable=False)    # 끝 위치
+    selected_text = Column(Text, nullable=False)    # 선택된 텍스트 (검색용)
+    
+    # DOM 위치 정보 (정확한 복원을 위해)
+    element_selector = Column(Text, nullable=True)  # CSS 선택자
+    start_container_xpath = Column(Text, nullable=True)  # 시작 컨테이너 XPath
+    end_container_xpath = Column(Text, nullable=True)    # 끝 컨테이너 XPath
+    
+    # 스타일 정보
+    highlight_color = Column(String(7), default="#FFFF00")  # HEX 색상 코드
+    highlight_type = Column(String(20), default="highlight")  # highlight, underline, etc.
+    
+    # 메타데이터
+    created_at = Column(DateTime(timezone=True), server_default=func.now())
+    updated_at = Column(DateTime(timezone=True), onupdate=func.now())
+    
+    # 관계
+    user = relationship("User", backref="highlights")
+    document = relationship("Document", back_populates="highlights")
+    note = relationship("Note", back_populates="highlight", uselist=False, cascade="all, delete-orphan")
+
+    def __repr__(self):
+        return f"<Highlight(id='{self.id}', text='{self.selected_text[:50]}...')>"