feat: track designer downloads and notifications

backend/app/main.py

@@ -1,6 +1,7 @@
 from fastapi import FastAPI, Request, Response
 from fastapi.middleware.cors import CORSMiddleware
 from fastapi.staticfiles import StaticFiles
+from sqlalchemy import inspect, text
 from app.core.config import settings
 from app.core.database import Base, engine
 from app.api import auth, works, orders, payment, upload
@@ -8,6 +9,25 @@ from app.api import auth, works, orders, payment, upload
 # 创建数据库表
 Base.metadata.create_all(bind=engine)
 
+
+def ensure_runtime_schema():
+    inspector = inspect(engine)
+    columns = {col["name"] for col in inspector.get_columns("download_records")}
+    statements = []
+    if "designer_name" not in columns:
+        statements.append("ALTER TABLE download_records ADD COLUMN designer_name VARCHAR(100)")
+    if "work_title" not in columns:
+        statements.append("ALTER TABLE download_records ADD COLUMN work_title VARCHAR(255)")
+    if "amount" not in columns:
+        statements.append("ALTER TABLE download_records ADD COLUMN amount FLOAT DEFAULT 0")
+    if statements:
+        with engine.begin() as conn:
+            for sql in statements:
+                conn.execute(text(sql))
+
+
+ensure_runtime_schema()
+
 # 创建 FastAPI 应用
 app = FastAPI(
     title=settings.PROJECT_NAME,