fix(avatar): recover BOXIM image replies

digital-avatar-app/backend/database.py

@@ -1,16 +1,30 @@
 import os
 
-from sqlalchemy import create_engine
+from sqlalchemy import create_engine, event
 from sqlalchemy.orm import sessionmaker, declarative_base, Session
 
 BASE_DIR = os.path.dirname(os.path.abspath(__file__))
 DB_FILE = os.path.join(BASE_DIR, "avatar.db")
 DATABASE_URL = os.getenv("DATABASE_URL", f"sqlite:///{DB_FILE}")
 
+IS_SQLITE = DATABASE_URL.startswith("sqlite:")
 engine = create_engine(
     DATABASE_URL,
-    connect_args={"check_same_thread": False} if DATABASE_URL.startswith("sqlite:") else {},
+    connect_args={"check_same_thread": False, "timeout": 30} if IS_SQLITE else {},
 )
+
+
+if IS_SQLITE:
+    @event.listens_for(engine, "connect")
+    def _configure_sqlite_connection(dbapi_connection, _connection_record):
+        cursor = dbapi_connection.cursor()
+        try:
+            cursor.execute("PRAGMA synchronous=NORMAL")
+            cursor.execute("PRAGMA busy_timeout=30000")
+        finally:
+            cursor.close()
+
+
 SessionLocal = sessionmaker(bind=engine, autoflush=False, expire_on_commit=False)
 Base = declarative_base()
 
@@ -26,6 +40,10 @@ def get_db():
 def init_db():
     import models
 
+    if IS_SQLITE:
+        with engine.connect() as conn:
+            conn.exec_driver_sql("PRAGMA journal_mode=WAL")
+            conn.commit()
     Base.metadata.create_all(bind=engine)
 
     # 轻量迁移：为已存在的表补充新列（SQLite 不支持自动 ALTER，逐列尝试）