feat: SWG 가스켓 전체 구성 정보 표시 개선

- H/F/I/O SS304/GRAPHITE/CS/CS 패턴에서 4개 구성요소 모두 표시
- 기존 SS304 + GRAPHITE → SS304/GRAPHITE/CS/CS로 완전한 구성 표시
- 외부링/필러/내부링/추가구성 모든 정보 포함
- 구매수량 계산 모달에서 정확한 재질 정보 확인 가능

backend/app/models.py

@@ -276,8 +276,7 @@ class RequirementType(Base):
     
     created_at = Column(DateTime, default=datetime.utcnow)
     
-    # 관계 설정
-    requirements = relationship("UserRequirement", back_populates="requirement_type")
+    # 관계 설정은 문자열 기반이므로 제거
 
 class UserRequirement(Base):
     """사용자 추가 요구사항"""
@@ -308,4 +307,145 @@ class UserRequirement(Base):
     
     # 관계 설정
     file = relationship("File", backref="user_requirements")
-    requirement_type_rel = relationship("RequirementType", back_populates="requirements")
+
+# ========== Tubing 시스템 모델들 ==========
+
+class TubingCategory(Base):
+    """Tubing 카테고리 (일반, VCR, 위생용 등)"""
+    __tablename__ = "tubing_categories"
+    
+    id = Column(Integer, primary_key=True, index=True)
+    category_code = Column(String(20), unique=True, nullable=False)
+    category_name = Column(String(100), nullable=False)
+    description = Column(Text)
+    is_active = Column(Boolean, default=True)
+    created_at = Column(DateTime, default=datetime.utcnow)
+    updated_at = Column(DateTime, default=datetime.utcnow)
+    
+    # 관계 설정
+    specifications = relationship("TubingSpecification", back_populates="category")
+
+class TubingSpecification(Base):
+    """Tubing 규격 마스터"""
+    __tablename__ = "tubing_specifications"
+    
+    id = Column(Integer, primary_key=True, index=True)
+    category_id = Column(Integer, ForeignKey("tubing_categories.id"))
+    spec_code = Column(String(50), unique=True, nullable=False)
+    spec_name = Column(String(200), nullable=False)
+    
+    # 물리적 규격
+    outer_diameter_mm = Column(Numeric(8, 3))
+    wall_thickness_mm = Column(Numeric(6, 3))
+    inner_diameter_mm = Column(Numeric(8, 3))
+    
+    # 재질 정보
+    material_grade = Column(String(100))
+    material_standard = Column(String(100))
+    
+    # 압력/온도 등급
+    max_pressure_bar = Column(Numeric(8, 2))
+    max_temperature_c = Column(Numeric(6, 2))
+    min_temperature_c = Column(Numeric(6, 2))
+    
+    # 표준 규격
+    standard_length_m = Column(Numeric(8, 3))
+    bend_radius_min_mm = Column(Numeric(8, 2))
+    
+    # 기타 정보
+    surface_finish = Column(String(100))
+    hardness = Column(String(50))
+    notes = Column(Text)
+    
+    is_active = Column(Boolean, default=True)
+    created_at = Column(DateTime, default=datetime.utcnow)
+    updated_at = Column(DateTime, default=datetime.utcnow)
+    
+    # 관계 설정
+    category = relationship("TubingCategory", back_populates="specifications")
+    products = relationship("TubingProduct", back_populates="specification")
+
+class TubingManufacturer(Base):
+    """Tubing 제조사"""
+    __tablename__ = "tubing_manufacturers"
+    
+    id = Column(Integer, primary_key=True, index=True)
+    manufacturer_code = Column(String(20), unique=True, nullable=False)
+    manufacturer_name = Column(String(200), nullable=False)
+    country = Column(String(100))
+    website = Column(String(500))
+    contact_info = Column(JSON)  # JSONB 타입
+    quality_certs = Column(JSON)  # JSONB 타입
+    is_active = Column(Boolean, default=True)
+    created_at = Column(DateTime, default=datetime.utcnow)
+    updated_at = Column(DateTime, default=datetime.utcnow)
+    
+    # 관계 설정
+    products = relationship("TubingProduct", back_populates="manufacturer")
+
+class TubingProduct(Base):
+    """제조사별 Tubing 제품 (품목번호 매핑)"""
+    __tablename__ = "tubing_products"
+    
+    id = Column(Integer, primary_key=True, index=True)
+    specification_id = Column(Integer, ForeignKey("tubing_specifications.id"))
+    manufacturer_id = Column(Integer, ForeignKey("tubing_manufacturers.id"))
+    
+    # 제조사 품목번호 정보
+    manufacturer_part_number = Column(String(200), nullable=False)
+    manufacturer_product_name = Column(String(300))
+    
+    # 가격/공급 정보
+    list_price = Column(Numeric(12, 2))
+    currency = Column(String(10), default='KRW')
+    lead_time_days = Column(Integer)
+    minimum_order_qty = Column(Numeric(10, 3))
+    standard_packaging_qty = Column(Numeric(10, 3))
+    
+    # 가용성 정보
+    availability_status = Column(String(50))
+    last_price_update = Column(DateTime)
+    
+    # 추가 정보
+    datasheet_url = Column(String(500))
+    catalog_page = Column(String(100))
+    notes = Column(Text)
+    
+    is_active = Column(Boolean, default=True)
+    created_at = Column(DateTime, default=datetime.utcnow)
+    updated_at = Column(DateTime, default=datetime.utcnow)
+    
+    # 관계 설정
+    specification = relationship("TubingSpecification", back_populates="products")
+    manufacturer = relationship("TubingManufacturer", back_populates="products")
+    material_mappings = relationship("MaterialTubingMapping", back_populates="tubing_product")
+
+class MaterialTubingMapping(Base):
+    """BOM 자재와 Tubing 제품 매핑"""
+    __tablename__ = "material_tubing_mapping"
+    
+    id = Column(Integer, primary_key=True, index=True)
+    material_id = Column(Integer, ForeignKey("materials.id", ondelete="CASCADE"))
+    tubing_product_id = Column(Integer, ForeignKey("tubing_products.id"))
+    
+    # 매핑 정보
+    confidence_score = Column(Numeric(3, 2))
+    mapping_method = Column(String(50))
+    mapped_by = Column(String(100))
+    mapped_at = Column(DateTime, default=datetime.utcnow)
+    
+    # 수량 정보
+    required_length_m = Column(Numeric(10, 3))
+    calculated_quantity = Column(Numeric(10, 3))
+    
+    # 검증 정보
+    is_verified = Column(Boolean, default=False)
+    verified_by = Column(String(100))
+    verified_at = Column(DateTime)
+    
+    notes = Column(Text)
+    created_at = Column(DateTime, default=datetime.utcnow)
+    
+    # 관계 설정
+    material = relationship("Material", backref="tubing_mappings")
+    tubing_product = relationship("TubingProduct", back_populates="material_mappings")