style: fix code formatting with black, isort, and flake8

Co-authored-by: christianlouis <361235+christianlouis@users.noreply.github.com>

app/utils/filename_utils.py

@@ -73,22 +73,22 @@ def get_unique_filepath_with_counter(directory, base_filename, extension=".pdf")
     """
     Returns a unique filepath in the specified directory using a numeric counter suffix.
     If 'base_filename.pdf' exists, it will append '-0001', '-0002', etc.
-    
+
     This function implements robust collision handling with zero-padded numeric suffixes
     as required for document storage organization.
-    
+
     Args:
         directory (str): Directory path where the file will be stored
         base_filename (str): Base name for the file (without extension)
         extension (str): File extension including the dot (default: ".pdf")
-        
+
     Returns:
         str: Full path to a unique filename
-        
+
     Examples:
         >>> get_unique_filepath_with_counter("/workdir/original", "2024-01-01_Invoice")
         "/workdir/original/2024-01-01_Invoice.pdf"  # If doesn't exist
-        
+
         >>> get_unique_filepath_with_counter("/workdir/original", "2024-01-01_Invoice")
         "/workdir/original/2024-01-01_Invoice-0001.pdf"  # If original exists
     """
@@ -96,7 +96,7 @@ def get_unique_filepath_with_counter(directory, base_filename, extension=".pdf")
     candidate = os.path.join(directory, base_filename + extension)
     if not os.path.exists(candidate):
         return candidate
-    
+
     # If base exists, try with counter suffix
     counter = 1
     while True:
@@ -106,7 +106,7 @@ def get_unique_filepath_with_counter(directory, base_filename, extension=".pdf")
         if not os.path.exists(candidate):
             return candidate
         counter += 1
-        
+
         # Sanity check to prevent infinite loops (very unlikely to reach)
         if counter > 9999:
             # Fall back to timestamp + UUID if somehow we have 10000 collisions