fix: resolve macOS FileNotFoundError and stabilize API error handling

Author: notsooamit

lexoid/core/conversion_utils.py

@@ -159,15 +159,16 @@ def handle_load_finished(status):
 
 
 def convert_doc_to_pdf(input_path: str, temp_dir: str) -> str:
+    input_path = os.path.abspath(input_path)
+    temp_dir = os.path.abspath(temp_dir)
     temp_path = os.path.join(
         temp_dir, os.path.splitext(os.path.basename(input_path))[0] + ".pdf"
     )
 
     # Convert the document to PDF
     # docx2pdf is not supported in linux. Use LibreOffice in linux instead.
     # May need to install LibreOffice if not already installed.
-    input_path = os.path.abspath(input_path)
-    temp_dir = os.path.abspath(temp_dir)
+
     if "linux" in sys.platform.lower():
         subprocess.run(
             [