style: Fix flake8 errors in database module and tests

- Remove whitespace from blank lines (W293)
- Fix trailing whitespace (W291)
- Add proper newline at end of file (W292)
- Fix import order with noqa comment (E402)
- Remove unused variable assignment
- Maintain proper spacing in function definitions

All timestamp parsing tests still pass after formatting fixes.
Clean flake8 output for database.py and test_database.py.

Author: natifridman

src/database.py

@@ -162,32 +162,32 @@ def parse_snowflake_timestamp(timestamp_str: str) -> str:
     """Parse Snowflake timestamp format and convert to ISO format"""
     if not timestamp_str or not isinstance(timestamp_str, str):
         return timestamp_str
-    
+
     try:
         # Handle format like "1753767533.658000000 1440"
         parts = timestamp_str.strip().split()
         if len(parts) >= 2:
             timestamp_part = parts[0]
             timezone_offset_minutes = int(parts[1])
-            
+
             # Convert to float to handle decimal seconds
             timestamp_float = float(timestamp_part)
-            
+
             # Create datetime from timestamp
             dt = datetime.fromtimestamp(timestamp_float, tz=timezone.utc)
-            
+
             # Apply timezone offset (offset is in minutes)
             offset_timedelta = timedelta(minutes=timezone_offset_minutes)
             dt_with_offset = dt + offset_timedelta
-            
+
             # Return in ISO format
             return dt_with_offset.isoformat()
         else:
             # Try parsing as simple timestamp
             timestamp_float = float(timestamp_str)
             dt = datetime.fromtimestamp(timestamp_float, tz=timezone.utc)
             return dt.isoformat()
-            
+
     except (ValueError, TypeError) as e:
         logger.debug(f"Could not parse timestamp '{timestamp_str}': {e}")
         return timestamp_str
@@ -201,20 +201,20 @@ def format_snowflake_row(row_data: List[Any], columns: List[str]) -> Dict[str, A
     result = {}
     # Date/time columns that should be parsed
     timestamp_columns = {
-        'CREATED', 'UPDATED', 'DUEDATE', 'RESOLUTIONDATE', 
+        'CREATED', 'UPDATED', 'DUEDATE', 'RESOLUTIONDATE',
         'ARCHIVEDDATE', '_FIVETRAN_SYNCED'
     }
-    
+
     for i in range(len(columns)):
         column_name = columns[i].upper()
         value = row_data[i]
-        
+
         # Parse timestamp columns
         if column_name in timestamp_columns and value:
             result[columns[i]] = parse_snowflake_timestamp(str(value))
         else:
             result[columns[i]] = value
-            
+
     return result