Additional bugfixes

backend/app/core/executor.py

@@ -23,5 +23,5 @@ def get_executor() -> ThreadPoolExecutor:
 def shutdown_executor() -> None:
     global _executor
     if _executor is not None:
-        _executor.shutdown(wait=False)
+        _executor.shutdown(wait=True)
         _executor = None

backend/app/core/export.py

@@ -2,6 +2,7 @@ from __future__ import annotations
 
 import io
 
+import openpyxl
 from reportlab.lib import colors
 from reportlab.lib.pagesizes import A4, landscape
 from reportlab.lib.styles import getSampleStyleSheet
@@ -57,6 +58,19 @@ def _pdf_table(rows: list[dict]) -> Table:
     return t
 
 
+def to_xlsx_bytes(rows: list[dict]) -> bytes:
+    """Serialise *rows* to a single-sheet XLSX workbook and return the raw bytes."""
+    wb = openpyxl.Workbook()
+    ws = wb.active
+    if rows:
+        ws.append(list(rows[0].keys()))
+        for row in rows:
+            ws.append([str(v) if v is not None else "" for v in row.values()])
+    buf = io.BytesIO()
+    wb.save(buf)
+    return buf.getvalue()
+
+
 def to_pdf_bytes(rows: list[dict], title: str, subtitle: str = "") -> bytes:
     """Serialise *rows* to a single-sheet PDF and return the raw bytes."""
     buf = io.BytesIO()