Normalize filenames and titles to NFC

src/documents/utils.py

@@ -1,5 +1,7 @@
 import logging
 import shutil
+import unicodedata
+from os import PathLike
 from os import utime
 from pathlib import Path
 from subprocess import CompletedProcess
@@ -16,6 +18,14 @@ def _coerce_to_path(
     return Path(source).resolve(), Path(dest).resolve()
 
 
+def normalize_nfc(value: str | PathLike[str] | None) -> str | None:
+    """Return NFC-normalized string for filesystem-safe comparisons."""
+
+    if value is None:
+        return None
+    return unicodedata.normalize("NFC", str(value))
+
+
 def copy_basic_file_stats(source: Path | str, dest: Path | str) -> None:
     """
     Copies only the m_time and a_time attributes from source to destination.