feat: Add Review (사용후기) board system with CC reward

- Backend: Review model, full API (public/user/admin endpoints)
- Frontend: list, detail, write/edit pages, admin management
- 1 CC reward for writing a review on completed vehicle requests
- Navigation updates (Header + admin sidebar)
- "Write Review" button on my-request page for completed requests

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

backend/app/models/__init__.py

@@ -19,6 +19,7 @@ from .exchange_rate import ExchangeRate, ExchangeRateHistory
 from .cc_package import CCPackage, DEFAULT_CC_PACKAGES
 from .visitor import VisitorLog, VisitorDailyStats, VisitorSession
 from .bulletin import BoardCategory, BoardPost
+from .review import Review
 
 __all__ = [
     "CarMaker",
@@ -66,4 +67,5 @@ __all__ = [
     "VisitorSession",
     "BoardCategory",
     "BoardPost",
+    "Review",
 ]

backend/app/models/review.py

@@ -0,0 +1,29 @@
+from sqlalchemy import Column, Integer, String, Text, Boolean, DateTime, ForeignKey, CheckConstraint
+from sqlalchemy.orm import relationship
+from sqlalchemy.sql import func
+
+from ..database import Base
+
+
+class Review(Base):
+    """User reviews for completed vehicle requests"""
+    __tablename__ = "reviews"
+    __table_args__ = (
+        CheckConstraint('rating >= 1 AND rating <= 5', name='check_rating_range'),
+    )
+
+    id = Column(Integer, primary_key=True, index=True)
+    request_id = Column(Integer, ForeignKey("vehicle_requests.id"), nullable=False, unique=True)
+    author_id = Column(Integer, ForeignKey("users.id"), nullable=False, index=True)
+    rating = Column(Integer, nullable=False)
+    title = Column(String(255), nullable=False)
+    content = Column(Text, nullable=False)
+    cc_rewarded = Column(Boolean, default=False)
+    is_published = Column(Boolean, default=True, index=True)
+    view_count = Column(Integer, default=0)
+    created_at = Column(DateTime(timezone=True), server_default=func.now(), index=True)
+    updated_at = Column(DateTime(timezone=True), onupdate=func.now())
+
+    # Relationships
+    request = relationship("VehicleRequest", backref="review")
+    author = relationship("User", backref="reviews")