fix until the canvas sort of works

backend/app/api/export.py

@@ -6,7 +6,7 @@ from fastapi import APIRouter, Depends, HTTPException, Query, status
 from fastapi.responses import StreamingResponse
 from sqlalchemy.orm import Session
 
-from app.core.deps import get_current_user, get_db
+from app.core.deps import get_current_user, get_db_sync
 from app.database.models.board import Board
 from app.database.models.board_image import BoardImage
 from app.database.models.image import Image
@@ -22,7 +22,7 @@ router = APIRouter(tags=["export"])
 async def download_image(
     image_id: UUID,
     current_user: User = Depends(get_current_user),
-    db: Session = Depends(get_db),
+    db: Session = Depends(get_db_sync),
 ) -> StreamingResponse:
     """
     Download a single image.
@@ -45,7 +45,7 @@ async def download_image(
 def export_board_zip(
     board_id: UUID,
     current_user: User = Depends(get_current_user),
-    db: Session = Depends(get_db),
+    db: Session = Depends(get_db_sync),
 ) -> StreamingResponse:
     """
     Export all images from a board as a ZIP file.
@@ -70,7 +70,7 @@ def export_board_composite(
     scale: float = Query(1.0, ge=0.5, le=4.0, description="Resolution scale (0.5x to 4x)"),
     format: str = Query("PNG", regex="^(PNG|JPEG)$", description="Output format (PNG or JPEG)"),
     current_user: User = Depends(get_current_user),
-    db: Session = Depends(get_db),
+    db: Session = Depends(get_db_sync),
 ) -> StreamingResponse:
     """
     Export board as a single composite image showing the layout.
@@ -97,7 +97,7 @@ def export_board_composite(
 def get_export_info(
     board_id: UUID,
     current_user: User = Depends(get_current_user),
-    db: Session = Depends(get_db),
+    db: Session = Depends(get_db_sync),
 ) -> dict:
     """
     Get information about board export (image count, estimated size).