Temporarily disable CSV uploads

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

site/routes/api_bp.py

@@ -42,13 +42,20 @@ def _disconnect_exceptions():
 def upload():
     """Upload files to session (один или несколько)."""
     sid = request.form.get("session", "")
-    if not sid:
-        sid = create_session()
     uploaded = request.files.getlist("files")
     if not uploaded:
         log.warning("upload: no files, sid=%s", sid)
         return jsonify({"ok": False, "error": "No file"}), 400
 
+    # CSV input is temporarily disabled so reliability testing can focus on the
+    # other document formats. Keep the CSV processing code in the core intact.
+    if any(safe_name(f.filename).lower().endswith(".csv") for f in uploaded):
+        log.warning("upload: CSV input is disabled")
+        return jsonify({"ok": False, "error": "CSV uploads are temporarily disabled"}), 400
+
+    if not sid:
+        sid = create_session()
+
     added = 0
     had_unnamed = False
     for f in uploaded: