fix: harden case files endpoints when sag_files table/schema is missing

app/modules/sag/backend/router.py

@@ -3158,11 +3158,17 @@ def _store_upload_file(upload_file: UploadFile, subdir: str):
 async def list_sag_files(sag_id: int):
     """List files attached to a case."""
     try:
+        if not _table_exists("sag_files"):
+            logger.warning("⚠️ sag_files table missing - returning empty file list for SAG-%s", sag_id)
+            return []
+
+        order_expr = "created_at DESC" if table_has_column("sag_files", "created_at") else "id DESC"
         query = """
             SELECT * FROM sag_files 
             WHERE sag_id = %s 
-            ORDER BY created_at DESC
+            ORDER BY {order_expr}
         """
+        query = query.format(order_expr=order_expr)
         files = execute_query(query, (sag_id,))
         # Add download URL
         if files:
@@ -3176,6 +3182,9 @@ async def list_sag_files(sag_id: int):
 @router.post("/sag/{sag_id}/files")
 async def upload_sag_files(sag_id: int, files: List[UploadFile] = File(...)):
     """Upload files to a case."""
+    if not _table_exists("sag_files"):
+        raise HTTPException(status_code=503, detail="sag_files table is missing. Run database migrations first")
+
     check = execute_query("SELECT id FROM sag_sager WHERE id = %s AND deleted_at IS NULL", (sag_id,))
     if not check:
         raise HTTPException(status_code=404, detail="Case not found")
@@ -3211,6 +3220,9 @@ async def download_sag_file(sag_id: int, file_id: int, download: bool = False):
     Args:
         download: If True, force download. If False (default), display inline in browser.
     """
+    if not _table_exists("sag_files"):
+        raise HTTPException(status_code=503, detail="sag_files table is missing. Run database migrations first")
+
     query = "SELECT * FROM sag_files WHERE id = %s AND sag_id = %s"
     result = execute_query(query, (file_id, sag_id))
     
@@ -3241,6 +3253,9 @@ async def download_sag_file(sag_id: int, file_id: int, download: bool = False):
 @router.get("/sag/{sag_id}/files/{file_id}/preview-image")
 async def preview_sag_pdf_as_image(sag_id: int, file_id: int, page: int = Query(1, ge=1), scale: float = Query(2.8, ge=1.0, le=5.0)):
     """Render a PDF page as PNG for consistent in-app preview sizing."""
+    if not _table_exists("sag_files"):
+        raise HTTPException(status_code=503, detail="sag_files table is missing. Run database migrations first")
+
     query = "SELECT * FROM sag_files WHERE id = %s AND sag_id = %s"
     result = execute_query(query, (file_id, sag_id))
 
@@ -3287,6 +3302,9 @@ async def preview_sag_pdf_as_image(sag_id: int, file_id: int, page: int = Query(
 @router.delete("/sag/{sag_id}/files/{file_id}")
 async def delete_sag_file(sag_id: int, file_id: int):
     """Delete a file."""
+    if not _table_exists("sag_files"):
+        raise HTTPException(status_code=503, detail="sag_files table is missing. Run database migrations first")
+
     query = "DELETE FROM sag_files WHERE id = %s AND sag_id = %s RETURNING stored_name"
     result = execute_query(query, (file_id, sag_id))